VISTRA CORP., 10-K filed on 2/26/2021
Annual Report
v3.20.4
Cover Page - USD ($)
12 Months Ended
Dec. 31, 2020
Feb. 23, 2021
Jun. 30, 2020
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2020    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-38086    
Entity Registrant Name Vistra Corp.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 36-4833255    
Entity Address, Address Line One 6555 Sierra Drive    
Entity Address, City or Town Irving,    
Entity Address, State or Province TX    
Entity Address, Postal Zip Code 75039    
City Area Code (214)    
Local Phone Number 812-4600    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 9,084,469,142
Entity Common Stock, Shares Outstanding   483,716,012  
Entity Central Index Key 0001692819    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Amendment Flag false    
Common stock, par value $0.01 per share      
Document Information [Line Items]      
Title of 12(b) Security Common stock, par value $0.01 per share    
Trading Symbol VST    
Security Exchange Name NYSE    
Warrant      
Document Information [Line Items]      
Title of 12(b) Security Warrants    
Trading Symbol VST.WS.A    
Security Exchange Name NYSE    
v3.20.4
Consolidated Statements of Operations - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Statement [Abstract]      
Operating revenues $ 11,443 $ 11,809 $ 9,144
Fuel, purchased power costs and delivery fees (5,174) (5,742) (5,036)
Operating costs (1,622) (1,530) (1,297)
Depreciation and amortization (1,737) (1,640) (1,394)
Selling, general and administrative expenses (1,035) (904) (926)
Impairment of long-lived assets (356) 0 0
Operating income 1,519 1,993 491
Other income 34 56 47
Other deductions (42) (15) (5)
Interest expense and related charges (630) (797) (572)
Impacts of Tax Receivable Agreement 5 (37) (79)
Equity in earnings of unconsolidated investment 4 16 17
Income (loss) before income taxes 890 1,216 (101)
Income tax (expense) benefit (266) (290) 45
Net income (loss) 624 926 (56)
Net loss attributable to noncontrolling interest 12 2 2
Net income (loss) attributable to Vistra $ 636 $ 928 $ (54)
Weighted average shares of common stock outstanding:      
Weighted average shares of common stock outstanding - basic 488,668,263 494,146,268 504,954,371
Weighted average shares of common stock outstanding - diluted 491,090,468 499,935,490 504,954,371
Net income (loss) per weighted average share of common stock outstanding:      
Net income (loss) per weighted average share of common stock outstanding - basic $ 1.30 $ 1.88 $ (0.11)
Net income (loss) per weighted average share of common stock outstanding - diluted $ 1.30 $ 1.86 $ (0.11)
v3.20.4
Consolidated Statements of Comprehensive Income (Loss) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Statement of Comprehensive Income [Abstract]      
Net income (loss) $ 624 $ 926 $ (56)
Other comprehensive loss, net of tax effects:      
Effects related to pension and other retirement benefit obligations (net of tax benefit of $5, $4 and $2) (18) (8) (6)
Adoption of new accounting standard 0 0 1
Total other comprehensive loss (18) (8) (5)
Comprehensive income (loss) 606 918 (61)
Comprehensive loss attributable to noncontrolling interest 12 2 2
Comprehensive income (loss) attributable to Vistra $ 618 $ 920 $ (59)
v3.20.4
Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Statement of Comprehensive Income [Abstract]      
Effects related to pension and other retirement obligations (tax) $ (5) $ (4) $ (2)
v3.20.4
Consolidated Statements of Cash Flows - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Cash flows — operating activities:      
Net income (loss) $ 624 $ 926 $ (56)
Adjustments to reconcile net income (loss) to cash provided by operating activities:      
Depreciation and amortization 2,048 1,876 1,533
Deferred income tax expense (benefit), net 230 281 (62)
Impairment of long-lived assets 356 0 0
Loss on disposal of investment in NELP 29 0 0
Unrealized net (gain) loss from mark-to-market valuations of commodities (231) (696) 380
Unrealized net loss from mark-to-market valuations of interest rate swaps 155 220 5
Change in asset retirement obligation liability 7 (48) (27)
Asset retirement obligation accretion expense 43 53 50
Impacts of Tax Receivables Agreement (5) 37 79
Bad debt expense 110 82 55
Stock-based compensation 65 47 73
Other, net (22) (12) 37
Changes in operating assets and liabilities:      
Accounts receivable — trade (33) (88) (207)
Inventories (59) (44) 61
Accounts payable — trade (40) (221) 90
Commodity and other derivative contractual assets and liabilities 27 98 (80)
Margin deposits, net (20) 170 (221)
Accrued interest (20) 80 (105)
Accrued taxes 22 (4) (64)
Accrued employee incentive 39 1 40
Tax Receivable Agreement payment 0 (2) (16)
Asset retirement obligation settlement (118) (121) (100)
Major plant outage deferral 2 (19) (22)
Other — net assets 219 (22) 73
Other — net liabilities (91) 142 (45)
Cash provided by operating activities 3,337 2,736 1,471
Cash flows — investing activities:      
Capital expenditures, including nuclear fuel purchases and LTSA prepayments (1,259) (713) (530)
Ambit acquisition (net of cash acquired) 0 (506) 0
Crius acquisition (net of cash acquired) 0 (374) 0
Cash acquired in the Merger 0 0 445
Proceeds from sales of nuclear decommissioning trust fund securities 433 431 252
Investments in nuclear decommissioning trust fund securities (455) (453) (274)
Proceeds from sales of environmental allowances 165 197 1
Purchases of environmental allowances (504) (322) (5)
Proceeds from sales of assets 24 6 7
Other, net 24 17 3
Cash used in investing activities (1,572) (1,717) (101)
Cash flows - financing activities:      
Issuances of long-term debt 0 6,507 1,000
Repayments/repurchases of debt (1,008) (7,109) (3,075)
Net borrowings/(payments) under accounts receivable securitization program (150) 111 339
Borrowings under Revolving Credit Facility 1,075 650 0
Repayments under Revolving Credit Facility (1,425) (300) 0
Debt tender offer and other debt financing fees (17) (203) (236)
Stock repurchase 0 (656) (763)
Dividends paid to stockholders (266) (243) 0
Other, net (5) 6 12
Cash used in financing activities (1,796) (1,237) (2,723)
Net change in cash, cash equivalents and restricted cash (31) (218) (1,353)
Cash, cash equivalents and restricted cash — beginning balance 475 693 2,046
Cash, cash equivalents and restricted cash — ending balance $ 444 $ 475 $ 693
v3.20.4
Consolidated Balance Sheets - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Current assets:    
Cash and cash equivalents $ 406 $ 300
Restricted cash 19 147
Trade accounts receivable — net 1,279 1,365
Inventories 515 469
Commodity and other derivative contractual assets 748 1,333
Margin deposits related to commodity contracts 257 202
Prepaid expense and other current assets 205 298
Total current assets 3,429 4,114
Restricted cash 19 28
Investments 1,759 1,537
Investment in unconsolidated subsidiary 0 124
Operating lease right-of-use assets 45 44
Property, plant and equipment — net 13,499 13,914
Goodwill 2,583 2,553
Identifiable intangible assets — net 2,446 2,748
Commodity and other derivative contractual assets 258 136
Accumulated deferred income taxes 838 1,066
Other noncurrent assets 332 352
Total assets 25,208 26,616
Current liabilities:    
Short-term borrowings 0 350
Accounts receivable securitization program 300 450
Long-term debt due currently 95 277
Trade accounts payable 880 947
Commodity and other derivative contractual liabilities 789 1,529
Margin deposits related to commodity contracts 33 8
Accrued income taxes 16 1
Accrued taxes other than income 210 200
Accrued interest 131 151
Asset retirement obligations 103 141
Operating lease liabilities 8 14
Other current liabilities 471 506
Total current liabilities 3,036 4,574
Long-term debt, less amounts due currently 9,235 10,102
Operating lease liabilities 40 41
Commodity and other derivative contractual liabilities 624 396
Accumulated deferred income taxes 1 2
Tax Receivable Agreement obligation 447 455
Asset retirement obligation 2,333 2,097
Other noncurrent liabilities and deferred credits 1,131 989
Total liabilities 16,847 18,656
Commitments and Contingencies
Total equity:    
Common stock (par value — $0.01; number of shares authorized — 1,800,000,000) (shares outstanding: December 31, 2020 — 489,305,888; December 31, 2019 — 487,698,111) 5 5
Treasury stock, at cost (shares: December 31, 2020 — 41,043,224; December 31, 2019 — 41,043,224) (973) (973)
Additional paid-in-capital 9,786 9,721
Retained deficit (399) (764)
Accumulated other comprehensive loss (48) (30)
Stockholders' equity 8,371 7,959
Noncontrolling interest in subsidiary (10) 1
Total equity 8,361 7,960
Total liabilities and equity $ 25,208 $ 26,616
v3.20.4
Consolidated Balance Sheets Consolidated Balance Sheets (Parenthetical)
Dec. 31, 2020
$ / shares
shares
Statement of Changes in Financial Position [Abstract]  
Common stock, par or stated value per share | $ / shares $ 0.01
Common stock, shares authorized 1,800,000,000
Common stock, shares outstanding 489,305,888
Treasury stock, common shares 41,043,224
v3.20.4
Consolidated Statement of Changes in Equity - USD ($)
$ in Millions
Total
Cumulative Effect, Period of Adoption, Adjustment [Member]
Common Stock [Member]
Treasury Stock [Member]
Additional Paid-in Capital [Member]
Retained Deficit [Member]
Retained Deficit [Member]
Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Member]
Total Stockholders' Equity [Member]
Total Stockholders' Equity [Member]
Cumulative Effect, Period of Adoption, Adjustment [Member]
Noncontrolling Interest in Subsidiary [Member]
AOCI Attributable to Noncontrolling Interest
Cumulative Effect, Period of Adoption, Adjustment [Member]
Balances at beginning of the period (Total Equity) at Dec. 31, 2017 $ 6,342   $ 4 $ 0 $ 7,765 $ (1,410)   $ (17) $ 6,342      
Increase (Decrease) in Stockholders' Equity [Roll Forward]                        
Stock and stock compensation awards issued in connection with the Merger 1,902   1   1,901       1,902      
Stock repurchases (778)     (778)         (778)      
Effects of stock-based compensation 72       72       72      
Tangible equity units acquired 369       369       369      
Warrants acquired 2       2       2      
Net income (loss) attributable to Vistra (54)         (54)     (54)      
Net loss attributable to noncontrolling interest (2)                   $ (2)  
Net income (loss) (56)                      
Pension and OPEB - change in funded status (6)             (6) (6)      
Investment by noncontrolling interest 6                   6  
Other (3)       (2) (1)     (3)      
Balances at end of the period (Total Equity) at Dec. 31, 2018 7,867 $ 17 5 (778) 10,107 (1,449) $ 16 (22) 7,863 $ 17 4 $ 1
Balances at beginning of the period (Total Equity) at Dec. 31, 2017 6,342   4 0 7,765 (1,410)   (17) 6,342      
Balances at end of the period (Total Equity) at Dec. 31, 2020 8,361 (4) 5 (973) 9,786 (399) (4) (48) 8,371 (4) (10)  
Balances at beginning of the period (Total Equity) at Dec. 31, 2018 7,867 17 5 (778) 10,107 (1,449) 16 (22) 7,863 17 4 $ 1
Increase (Decrease) in Stockholders' Equity [Roll Forward]                        
Stock repurchases (641)     (641)         (641)      
Shares issued for tangible equity unit contracts 0     446 (446)       0      
Effects of stock-based compensation 62       62       62      
Net income (loss) attributable to Vistra 928         928     928      
Net loss attributable to noncontrolling interest (2)                   (2)  
Net income (loss) 926                      
Dividends declared on common stock (243)         (243)     (243)      
Pension and OPEB - change in funded status (8)             (8) (8)      
Other (1)       (2) 2     0   (1)  
Balances at end of the period (Total Equity) at Dec. 31, 2019 7,960 (2) 5 (973) 9,721 (764) (2) (30) 7,959 (2) 1  
Increase (Decrease) in Stockholders' Equity [Roll Forward]                        
Effects of stock-based compensation 65       65       65      
Net income (loss) attributable to Vistra 636         636     636      
Net loss attributable to noncontrolling interest (12)                   (12)  
Net income (loss) 624                      
Dividends declared on common stock (266)         (266)     (266)      
Pension and OPEB - change in funded status (18)             (18) (18)      
Investment by noncontrolling interest 1                   1  
Other (1)       0 (1)     (1)      
Balances at end of the period (Total Equity) at Dec. 31, 2020 $ 8,361 $ (4) $ 5 $ (973) $ 9,786 $ (399) $ (4) $ (48) $ 8,371 $ (4) $ (10)  
v3.20.4
Business And Significant Accounting Policies
12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]  
Business And Significant Accounting Policies BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES
Description of Business

References in this report to "we," "our," "us" and "the Company" are to Vistra and/or its subsidiaries, as apparent in the context. See Glossary for defined terms.

Vistra is a holding company operating an integrated retail and electric power generation business primarily in markets throughout the U.S. Through our subsidiaries, we are engaged in competitive energy market activities including power generation, wholesale energy sales and purchases, commodity risk management and retail sales of electricity and natural gas to end users. Effective July 2, 2020, we changed our name from Vistra Energy Corp. to Vistra Corp. (Vistra) to distinguish from companies that are involved in the exploring for, producing, refining, or transporting fossil fuels (many of which use "energy" in their names) and to better reflect or integrated business model, which combines a retail electricity and natural gas business focused on serving its customers with new and innovative products and services and an electric power generation business powering the communities we serve with safe, reliable power.

Vistra has six reportable segments: (i) Retail, (ii) Texas, (iii) East, (iv) West, (v) Sunset and (vi) Asset Closure. In the third quarter of 2020, Vistra updated its reportable segments to reflect changes in how the Company's Chief Operating Decision Maker (CODM) makes operating decisions, assesses performance and allocates resources. Management believes that the revised reportable segments provide enhanced transparency into the Company's long-term sustainable assets and its commitment to managing the retirement of economically and environmentally challenged plants. The following is a summary of the updated segments:

The Sunset segment represents plants with announced retirement plans that were previously reported in the ERCOT, PJM and MISO segments. As we announced significant plant closures in the third quarter of 2020, management believes it is important to have a segment which differentiates between operating plants with defined retirement plans and operating plants without defined retirement plans.
The East segment represents Vistra's electricity generation operations in the Eastern Interconnection of the U.S. electric grid, other than assets that are now part of the Sunset or Asset Closure segments, respectively, and includes operations in PJM, ISO-NE and NYISO that were previously reported in the PJM and NY/NE segments, respectively.
The West segment represents Vistra's electricity generation operations in CAISO and was previously reported in the Corporate and Other non-segment. As reflected by the Moss Landing and Oakland ESS projects (see Note 3), the Company expects to expand its operations in the West segment.

In addition, the ERCOT segment was renamed the Texas segment. There were no changes to the Retail and Asset Closure segments. All historical segment results within these consolidated financial statements have been recast to be in alignment with our new segmentation. See Note 20 for further information concerning reportable business segments.

Ambit Transaction

On November 1, 2019, an indirect, wholly owned subsidiary of Vistra completed the acquisition of Ambit (Ambit Transaction). Because the Ambit Transaction closed on November 1, 2019, Vistra's consolidated financial statements and the notes related thereto do not include the financial condition or the operating results of Ambit and its subsidiaries prior to November 1, 2019. See Note 2 for a summary of the Ambit Transaction.

Crius Transaction

On July 15, 2019, an indirect, wholly owned subsidiary of Vistra completed the acquisition of the equity interests of two wholly owned subsidiaries of Crius that indirectly owned the operating business of Crius (Crius Transaction). Because the Crius Transaction closed on July 15, 2019, Vistra's consolidated financial statements and the notes related thereto do not include the financial condition or the operating results of Crius and its subsidiaries prior to July 15, 2019. See Note 2 for a summary of the Crius Transaction.
Dynegy Merger Transaction

On the Merger Date, Vistra and Dynegy completed the transactions contemplated by the Merger Agreement. Pursuant to the Merger Agreement, Dynegy merged with and into Vistra, with Vistra continuing as the surviving corporation. Because the Merger closed on April 9, 2018, Vistra's consolidated financial statements and the notes related thereto do not include the financial condition or the operating results of Dynegy prior to April 9, 2018. See Note 2 for a summary of the Merger transaction and business combination accounting.

COVID-19 Pandemic

In March 2020, the World Health Organization categorized the novel coronavirus (COVID-19) as a pandemic, and U.S. Government declared the COVID-19 outbreak a national emergency. The U.S. government has deemed electricity generation, transmission and distribution as "critical infrastructure" providing essential services during this global emergency. As a provider of critical infrastructure, Vistra has an obligation to provide critically needed power to homes, businesses, hospitals and other customers. Vistra remains focused on protecting the health and well-being of its employees and the communities in which it operates while assuring the continuity of its business operations.

The Company's consolidated financial statements reflect estimates and assumptions made by management that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and reported amounts of revenue and expenses during the reporting periods presented. The Company considered the impact of COVID-19 on the assumptions and estimates used and determined that there have been no material adverse impacts on the Company's results of operations for the year ended December 31, 2020.

In response to the global pandemic related to COVID-19, the CARES Act was signed into law on March 27, 2020. See Note 7 for a summary of certain anticipated tax-related impacts of the CARES Act to the Company.

February 2021 Weather Event

In February 2021, a severe winter storm with extremely cold temperatures affected much of the U.S., including Texas. This severe weather resulted in surging demand for power, gas supply shortages, operational challenges for generators, and a significant load shed event that was ordered by ERCOT beginning on February 15, 2021 and continuing through February 18, 2021. At the time we issued these financial statements, we expect the impact of the weather event to be a material loss that will be reflected in our first quarter 2021 results of operations. However, uncertainty exists with respect to the financial impact of the weather event due in part to outstanding pricing and settlement data from ERCOT, the outcome of potential litigation arising from the event, or any corrective action taken by the State of Texas, ERCOT, the RCT, or the PUCT to resettle pricing across any portion of the supply chain (i.e. fuel supply, wholesale pricing of generation, or allocating the financial impacts of market-wide load shed ratably across all retail market participants), that is currently being considered or may be considered by any such parties.

Basis of Presentation

The consolidated financial statements have been prepared in accordance with U.S. GAAP and on the same basis as the audited financial statements included in our 2019 Form 10-K. All intercompany items and transactions have been eliminated in consolidation. All dollar amounts in the financial statements and tables in the notes are stated in millions of U.S. dollars unless otherwise indicated.

Use of Estimates

Preparation of financial statements requires estimates and assumptions about future events that affect the reporting of assets and liabilities at the balance sheet dates and the reported amounts of revenue and expense, including fair value measurements, estimates of expected obligations, judgments related to the potential timing of events and other estimates. In the event estimates and/or assumptions prove to be different from actual amounts, adjustments are made in subsequent periods to reflect more current information.
Derivative Instruments and Mark-to-Market Accounting

We enter into contracts for the purchase and sale of electricity, natural gas, coal, uranium and other commodities utilizing instruments such as options, swaps, futures and forwards primarily to manage commodity price and interest rate risks. If the instrument meets the definition of a derivative under accounting standards related to derivative instruments and hedging activities, changes in the fair value of the derivative are recognized in net income as unrealized gains and losses. This recognition is referred to as mark-to-market accounting. The fair values of our unsettled derivative instruments under mark-to-market accounting are reported in the consolidated balance sheets as commodity and other derivative contractual assets or liabilities. We report derivative assets and liabilities in the consolidated balance sheets without taking into consideration netting arrangements we have with counterparties. Margin deposits that contractually offset these assets and liabilities are reported separately in the consolidated balance sheets, except for certain margin amounts related to changes in fair value on CME transactions that are legally characterized as settlement of derivative contracts rather than collateral. When derivative instruments are settled and realized gains and losses are recorded, the previously recorded unrealized gains and losses and derivative assets and liabilities are reversed. See Notes 15 and 16 for additional information regarding fair value measurement and commodity and other derivative contractual assets and liabilities. A commodity-related derivative contract may be designated as a normal purchase or sale if the commodity is to be physically received or delivered for use or sale in the normal course of business. If designated as normal, the derivative contract is accounted for under the accrual method of accounting (not marked-to-market) with no balance sheet or income statement recognition of the contract until settlement.

Because derivative instruments are frequently used as economic hedges, accounting standards related to derivative instruments and hedging activities allow for hedge accounting, which provides for the designation of such instruments as cash flow or fair value hedges if certain conditions are met. At December 31, 2020 and 2019, there were no derivative positions accounted for as cash flow or fair value hedges.

We report commodity hedging and trading results as revenue, fuel expense or purchased power in the consolidated statements of operations depending on the type of activity. Electricity hedges, financial natural gas hedges and trading activities are primarily reported as revenue. Physical or financial hedges for coal, diesel or uranium, along with physical natural gas trades, are primarily reported as fuel expense. Realized and unrealized gains and losses associated with interest rate swap transactions are reported in the consolidated statements of operations in interest expense.

Revenue Recognition

Revenue is recognized when electricity is delivered to our customers in an amount that we expect to invoice for volumes delivered or services provided. Sales tax is excluded from revenue. Energy sales and services that have been delivered but not billed by period end are estimated. Accrued unbilled revenues are based on estimates of customer usage since the date of the last meter reading provided by the independent system operators or electric distribution companies. Estimated amounts are adjusted when actual usage is known and billed.

We record wholesale generation revenue when volumes are delivered or services are performed for transactions that are not accounted for on a mark-to-market basis. These revenues primarily consist of physical electricity sales to the ISO/RTO, ancillary service revenue for reliability services, capacity revenue for making installed generation and demand response available for system reliability requirements, and certain other electricity sales contracts. See Note 5 for detailed descriptions of revenue from contracts with customers. See Derivative Instruments and Mark-to-Market Accounting for revenue recognition related to derivative contracts.

Advertising Expense

We expense advertising costs as incurred and include them within SG&A expenses. Advertising expenses totaled $43 million, $49 million and $46 million for the year ended December 31, 2020, 2019 and 2018, respectively.

Impairment of Long-Lived Assets

We evaluate long-lived assets (including intangible assets with finite lives) for impairment whenever indications of impairment exist. The carrying value of such assets is deemed to be impaired if the projected undiscounted cash flows are less than the carrying value. If there is such impairment, a loss is recognized based on the amount by which the carrying value exceeds the fair value. Fair value is determined primarily by discounted cash flows, supported by available market valuations, if applicable. See Note 21 for details of impairments of long-lived assets recorded in 2020.
Finite-lived intangibles identified as a result of fresh start reporting or purchase accounting are amortized over their estimated useful lives based on the expected realization of economic effects. See Note 6 for details of intangible assets with finite lives, including discussion of fair value determinations.

Goodwill and Intangible Assets with Indefinite Lives

As part of fresh start reporting and purchase accounting, reorganization value or the purchase consideration is generally allocated, first, to identifiable tangible assets and liabilities, identifiable intangible assets and liabilities, then any remaining excess reorganization value is allocated to goodwill. We evaluate goodwill and intangible assets with indefinite lives for impairment at least annually, or when indications of impairment exist. We have established October 1 as the date we evaluate goodwill and intangible assets with indefinite lives for impairment. See Note 6 for details of goodwill and intangible assets with indefinite lives, including discussion of fair value determinations.

Nuclear Fuel

Nuclear fuel is capitalized and reported as a component of our property, plant and equipment in our consolidated balance sheets. Amortization of nuclear fuel is calculated on the units-of-production method and is reported as a component of fuel, purchased power costs and delivery fees in our consolidated statements of operations.

Major Maintenance Costs

Major maintenance costs incurred during generation plant outages are deferred and amortized into operating costs over the period between the major maintenance outages for the respective asset. Other routine costs of maintenance activities are charged to expense as incurred and reported as operating costs in our consolidated statements of operations.

Defined Benefit Pension Plans and OPEB Plans

On the Merger Date, Vistra assumed the pension and OPEB plans that Dynegy had provided to certain of its eligible employees and retirees. The excess of the benefit obligations over the fair value of plan assets was recognized as a liability. See Note 2 for additional information regarding the Merger.

Certain health care and life insurance benefits are offered to eligible employees and their dependents upon the retirement of such employee from the company. Pension benefits are offered to eligible employees under collective bargaining agreements based on either a traditional defined benefit formula or a cash balance formula. Costs of pension and OPEB plans are dependent upon numerous factors, assumptions and estimates.

See Note 17 for additional information regarding pension and OPEB plans.

Stock-Based Compensation

Stock-based compensation is accounted for in accordance with ASC 718, Compensation - Stock Compensation. The fair value of our non-qualified stock options is estimated on the date of grant using the Black-Scholes option-pricing model. Forfeitures are recognized as they occur. We recognize compensation expense for graded vesting awards on a straight-line basis over the requisite service period for the entire award. See Note 18 for additional information regarding stock-based compensation.

Sales and Excise Taxes

Sales and excise taxes are accounted for as "pass through" items on the consolidated balance sheets with no effect on the consolidated statements of operations (i.e., the tax is billed to customers and recorded as trade accounts receivable with an offsetting amount recorded as a liability to the taxing jurisdiction in other current liabilities in our consolidated statements of operations).
Franchise and Revenue-Based Taxes

Unlike sales and excise taxes, franchise and revenue-based taxes are not "pass through" items. These taxes are imposed on us by state and local taxing authorities, based on revenues or kWh delivered, as a cost of doing business and are recorded as an expense. Rates we charge to customers are intended to recover our costs, including the franchise and revenue-based receipt taxes, but we are not acting as an agent to collect the taxes from customers. We report franchise and revenue-based taxes in SG&A expense in our consolidated statements of operations.

Income Taxes

On the Merger Date, Vistra and Dynegy effected a merger transaction that for tax purposes was treated as a tax-free reorganization in which Vistra survived as the parent entity. In general, all of Dynegy's tax basis and attributes were transferred to Vistra, including approximately $4.5 billion of utilizable NOLs and refundable alternative minimum tax (AMT) tax credits.

Investment tax credits are accounted for under the deferral method, which resulted in a reduction to the basis of our solar and battery storage facilities of zero, $2 million and $78 million and a corresponding increase in the deferred tax assets in 2020, 2019 and 2018, respectively.

Deferred income taxes are provided for temporary differences between the book and tax basis of assets and liabilities as required under accounting rules. See Note 7.

We report interest and penalties related to uncertain tax positions as current income tax expense. See Note 7.

Tax Receivable Agreement (TRA)

The Company accounts for its obligations under the TRA as a liability in our consolidated balance sheets (see Note 8). The carrying value of the TRA obligation represents the discounted amount of projected payments under the TRA. The projected payments are based on certain assumptions, including but not limited to (a) the federal corporate income tax rate, (b) estimates of our taxable income in the current and future years and (c) additional states that Vistra operates in, including the relevant tax rate and apportionment factor for each state. Our taxable income takes into consideration the current federal tax code and reflects our current estimates of future results of the business.

The carrying value of the obligation is being accreted to the amount of the gross expected obligation using the effective interest method. Changes in the estimated amount of this obligation resulting from changes to either the timing or amount of TRA payments are recognized in the period of change and measured using the discount rate inherent in the initial fair value of the obligation. These changes are included on our consolidated statements of operations under the heading of Impacts of Tax Receivable Agreement.

Accounting for Contingencies

Our financial results may be affected by judgments and estimates related to loss contingencies. Accruals for loss contingencies are recorded when management determines that it is probable that a liability has been incurred and that such economic loss can be reasonably estimated. Such determinations are subject to interpretations of current facts and circumstances, forecasts of future events and estimates of the financial impacts of such events. See Note 13 for a discussion of contingencies.

Cash and Cash Equivalents

For purposes of reporting cash and cash equivalents, temporary cash investments purchased with a remaining maturity of three months or less are considered cash equivalents.

Restricted Cash

The terms of certain agreements require the restriction of cash for specific purposes. See Note 21 for more details regarding restricted cash.
Property, Plant and Equipment

Property, plant and equipment has been recorded at estimated fair values at the time of acquisition for assets acquired or at cost for capital improvements and individual facilities developed (see Notes 2 and 3). Significant improvements or additions to our property, plant and equipment that extend the life of the respective asset are capitalized at cost, while other costs are expensed when incurred. The cost of self-constructed property additions includes materials and both direct and indirect labor, including payroll-related costs. Interest related to qualifying construction projects and qualifying software projects is capitalized in accordance with accounting guidance related to capitalization of interest cost. See Note 21.

Depreciation of our property, plant and equipment (except for nuclear fuel) is calculated on a straight-line basis over the estimated service lives of the properties. Depreciation expense is calculated on an asset-by-asset basis. Estimated depreciable lives are based on management's estimates of the assets' economic useful lives. See Note 21.

Asset Retirement Obligations (ARO)

A liability is initially recorded at fair value for an asset retirement obligation associated with the legal obligation associated with law, regulatory, contractual or constructive retirement requirements of tangible long-lived assets in the period in which it is incurred if a fair value is reasonably estimable. At initial recognition of an ARO obligation, an offsetting asset is also recorded for the long-lived asset that the liability corresponds with, which is subsequently depreciated over the estimated useful life of the asset. These liabilities primarily relate to our nuclear generation plant decommissioning, land reclamation related to lignite mining and removal of lignite/coal-fueled plant ash treatment facilities. Over time, the liability is accreted for the change in present value and the initial capitalized costs are depreciated over the remaining useful lives of the assets. Generally, changes in estimates related to ARO obligations are recorded as increases or decreases to the liability and related asset as information becomes available. Changes in estimates related to assets that have been retired or for which capitalized costs are not recoverable are recorded as operating costs in the consolidated statements of operations. See Note 21.

Regulatory Asset or Liability

The costs to ultimately decommission the Comanche Peak nuclear power plant are recoverable through the regulatory rate making process as part of Oncor's delivery fees. As a result, the asset retirement obligation and the investments in the decommissioning trust are accounted for as rate regulated operations. Changes in these accounts, including investment income and accretion expense, do not impact net income, but are reported as a change in the corresponding regulatory asset or liability balance that is reflected in our consolidated balance sheets as other noncurrent assets or other noncurrent liabilities and deferred credits.

Inventories

Inventories consist of materials and supplies, fuel stock and natural gas in storage. Materials and supplies inventory is valued at weighted average cost and is expensed or capitalized when used for repairs/maintenance or capital projects, respectively. Fuel stock and natural gas in storage are reported at the lower of cost (calculated on a weighted average basis) or net realizable value. We expect to recover the value of inventory costs in the normal course of business. See Note 21.

Investments

Investments in a nuclear decommissioning trust fund are carried at current market value in the consolidated balance sheets. Assets related to employee benefit plans represent investments held to satisfy deferred compensation liabilities and are recorded at current market value. See Note 21 for discussion of these and other investments.

Unconsolidated Investments

We use the equity method of accounting for investments in affiliates over which we exercise significant influence. Our share of net income from these affiliates is recorded to equity in earnings of unconsolidated investment in the consolidated statements of operations. See Note 21.
Noncontrolling Interest

Noncontrolling interest is comprised of the 20% of Electric Energy, Inc. (EEI) that we do not own. EEI is our consolidated subsidiary that owns a coal facility in Joppa, Illinois. This noncontrolling interest is classified as a component of equity separate from stockholders' equity in the consolidated balance sheets.

Treasury Stock

Treasury stock purchases are accounted for under the cost method whereby the entire cost of the acquired stock is recorded as treasury stock, which is presented in our consolidated balance sheets as a reduction to additional paid-in capital. See Note 14.

Leases

At the inception of a contract we determine if it is or contains a lease, which involves the contract conveying the right to control the use of explicitly or implicitly identified property, plant, or equipment for a period of time in exchange for consideration.

Right-of-use (ROU) assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the commencement date of the underlying lease based on the present value of lease payments over the lease term. We use our secured incremental borrowing rate based on the information available at the lease commencement date to determine the present value of lease payments. Operating leases are included in operating lease ROU assets, operating lease liabilities (current) and operating lease liabilities (noncurrent) on our consolidated balance sheet. Finance leases are included in property, plant and equipment, other current liabilities and other noncurrent liabilities and deferred credits on our consolidated balance sheet. Lease term includes options to extend or terminate the lease when it is reasonably certain that we will exercise the option. We apply the practical expedient permitted by ASC 842 to not separate lease and non-lease components for a majority of our lease asset classes.

Leases with an initial lease term of 12 months or less are not recorded on the balance sheet; we recognize lease expense for these leases on a straight-line basis over the lease term.

We also present lessor sublease income on a net basis against the related lessee lease expense.

Adoption of Accounting Standards Issued Prior to 2020

Simplifying the Accounting for Income Taxes — In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2019-12, Simplifying the Accounting for Income Taxes (Topic 740). The ASU enhances and simplifies various aspects of the income tax accounting guidance including the elimination of certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. We adopted all provisions of this ASU in the first quarter of 2020, and it did not have a material impact on our financial statements.

Changes to the Disclosure Requirements for Fair Value Measurement — In August 2018, the FASB issued ASU 2018-13, Changes to the Disclosure Requirements for Fair Value Measurement. The ASU removes disclosure requirements for (a) the reasons for transfers between Level 1 and Level 2, (b) the policy for timing of transfers between levels and (c) the valuation processes for Level 3. The ASU requires new disclosures around (a) the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and (b) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. We adopted this ASU in the first quarter of 2020, and the updated disclosures are included in Note 15.
Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract — In August 2018, the FASB issued ASU 2018-15, Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. The ASU requires a customer in a cloud hosting arrangement that is a service contract to determine which implementation costs to capitalize and which costs to expense based on the project stage of the implementation. The ASU also requires the customer to expense the capitalized implementation costs over the term of the hosting arrangement. The customer is required to apply the existing impairment and abandonment guidance on the capitalized implementation costs. We adopted this ASU in the first quarter of 2020, and it did not have a material impact on our financial statements.

Financial Instruments—Credit Losses — In June 2016, the FASB issued ASU 2016-13, Financial Instruments — Credit Losses. The ASU requires organizations to measure all expected credit losses for financial instruments held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. We adopted this ASU in the first quarter of 2020, and it did not have a material impact on our financial statements.

Leases — On January 1, 2019, we adopted Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) and all related amendments (new lease standard) using the modified retrospective method with the cumulative-effect adjustment to the opening balance of retained deficit for all contracts outstanding at the time of adoption. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. We expect the impact of the adoption of the new lease standard to be immaterial to our net income on an ongoing basis. The impact of adopting the new lease standard primarily relates to recognition of lease liabilities and ROU assets for all leases classified as operating leases. Under the new lease standard, each ROU asset will be amortized over the lease term and liability settled at the end of the lease term. We recognized the effect of initially applying the new lease standard by recording ROU assets of $85 million and lease liabilities of $123 million in our consolidated balance sheet. See Note 12 for the disclosures required by the new lease standard.

Changes to the Disclosure Requirements for Defined Benefit Plans In August 2018, the Financial Accounting Standards Board (FASB) issued ASU 2018-14, Changes to the Disclosure Requirements for Defined Benefit Plans. The ASU removes disclosure requirements for (a) the amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost over the next fiscal year, (b) related party disclosures about the amount of future annual benefits covered by insurance and annuity contracts and significant transactions between the employer or related parties and the plan and (c) the effects of a one-percentage-point change in assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic benefit costs and benefit obligation for postretirement health care benefits. The ASU requires new disclosures for (a) the weighted-average interest crediting rates for cash balance plans and other plans with promised interest crediting rates and (b) an explanation of the reasons for significant gains and losses related to changes in the benefit obligation for the period. We adopted this ASU in the fourth quarter of 2018, and the updated disclosures are included in Note 17.

Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The ASU permits the reclassification of income tax effects of the TCJA on items within accumulated other comprehensive income (AOCI) to retained earnings. We adopted this ASU in the fourth quarter of 2018, and the impact was additional tax expense to AOCI of $1 million with the offset to retained deficit (see Note 7).

Revenue from Contracts with Customers On January 1, 2018, we adopted Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (Topic 606) and all related amendments (new revenue standard) using the modified retrospective method for all contracts outstanding at the time of adoption. We recognized the cumulative effect of initially applying the revenue standard as an adjustment to the opening balance of retained deficit. The impact of the adoption of the revenue standard was immaterial and we expect the adoption to continue to be immaterial to our net income on an ongoing basis. Our retail energy charges and wholesale generation, capacity and contract revenues will continue to be recognized when electricity and other services are delivered to our customers. The impact of adopting the revenue standard primarily relates to the deferral of acquisition costs associated with retail contracts with customers that were previously expensed as incurred. Under the revenue standard, these amounts are capitalized and amortized over the expected life of the customer.
Adoption of Accounting Standards Issued in 2020

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The ASU provides optional expedients and exceptions for applying GAAP to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another rate that is expected to be discontinued. The amendments in the ASU are effective for all entities as of March 12, 2020 through December 31, 2022. The adoption of this guidance did not have a material impact on our financial statements.

In March 2020, the SEC amended Rule 3-10 of Regulation S-X regarding financial disclosure requirements for registered debt offerings involving subsidiaries as either issuers or guarantors and affiliates whose securities are pledged as collateral. This new guidance narrows the circumstances that require separate financial statements of subsidiary issuers and guarantors and streamlines the alternative disclosures required in lieu of those statements. This rule is effective January 4, 2021 with earlier adoption permitted. We elected to adopt this rule in the first quarter of 2020. Accordingly, summarized financial information has been presented only for the issuer and guarantors of the Company's registered debt securities, and the location of the required disclosures has been moved outside the Notes to the Consolidated Financial Statements and is provided in Part II, Item 7 Management's Discussion and Analysis of Financial Condition and Results of Operations under Financial Condition Guarantor Summary Financial Information. In October 2020, the FASB issued ASU 2020-09, Debt (Topic 470) Amendments to SEC Paragraphs Pursuant to SEC Release No. 33-10762, to reflect the SEC's new disclosure rules on guaranteed debt securities adopted by the Company.
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Notes)
12 Months Ended
Dec. 31, 2020
Business Combinations [Abstract]  
Acquisitions, Merger Transaction and Business Combination Accounting ACQUISITIONS, MERGER TRANSACTION AND BUSINESS COMBINATION ACCOUNTING
Ambit Transaction

On November 1, 2019 (Ambit Acquisition Date), Volt Asset Company, Inc., an indirect, wholly owned subsidiary of Vistra, completed the Ambit Transaction. Ambit is an energy retailer selling both electricity and natural gas products to residential and small business customers in 17 states. Vistra funded the purchase price of $555 million (including cash acquired and net working capital) using cash on hand. All of Ambit's outstanding debt was repaid from the purchase price at closing and not assumed by Vistra.

Crius Transaction

On July 15, 2019 (Crius Acquisition Date), Vienna Acquisition B.C. Ltd., an indirect, wholly owned subsidiary of Vistra, completed the acquisition of the equity interests of two wholly owned subsidiaries of Crius that indirectly own the operating business of Crius. Crius is an energy retailer selling both electricity and natural gas products to residential and small business customers in 19 states. Vistra funded the purchase price of $400 million (including $382 million for outstanding trust units) using cash on hand. In addition, Vistra assumed $140 million of outstanding debt and acquired $26 million of cash at the closing of the Crius Transaction. See Note 11 for discussion of debt assumed in the Crius Transaction.

Ambit and Crius Business Combination Accounting

We believe the Ambit Transaction has (i) augmented Vistra's existing retail marketing capabilities with additional direct selling capability and a proprietary technology platform, (ii) reduced risk and aided expansion into higher margin channels by improving Vistra's match of its generation to load profile due to a high degree of overlap of Vistra's generation fleet with Ambit's approximately 11 TWh of annual load, primarily in ERCOT and PJM and (iii) enhanced the integrated value proposition through collateral and transaction efficiencies, particularly via Ambit's retail electric portfolio.

We believe the Crius Transaction has (i) reduced risk and aided expansion into higher margin channels by improving Vistra's match of its generation to load profile due to a high degree of overlap of Vistra's generation fleet with Crius' approximately 10 TWh of annual electricity load, (ii) established a platform for growth by leveraging Vistra's existing retail marketing capabilities and Crius' experienced team and (iii) enhanced the integrated value proposition through collateral and transaction efficiencies, particularly via Crius' retail electric portfolio.
Each of the Ambit Transaction and Crius Transaction, respectively, was accounted for in accordance with ASC 805, Business Combinations (ASC 805), with identifiable assets acquired and liabilities assumed recorded at their estimated fair values on the Ambit Acquisition Date and Crius Acquisition Date, respectively. The combined results of operations are reported in our consolidated financial statements beginning as of the respective Ambit Acquisition Date and Crius Acquisition Date. A summary of the techniques used to estimate the fair value of the identifiable assets and liabilities, as well as their classification within the fair value hierarchy (see Note 15), is listed below:

Working capital was valued using available market information (Level 2).
Acquired derivatives were valued using the methods described in Note 15 (Level 2 or Level 3).
Acquired retail customer relationship was valued based on discounted cash flow analysis of acquired customers and estimated attrition rates (Level 3).
Crius' long-term debt was valued using a market approach (Level 2).

The following table summarizes the allocation of the purchase price to the fair value amounts recognized for the assets acquired and liabilities assumed related to the Ambit Transaction and Crius Transaction, respectively, as of the Ambit Acquisition Date and Crius Acquisition Date, respectively. The Ambit Transaction purchase price was $555 million (including cash acquired and net working capital) and the Crius Transaction purchase price was $400 million. The final purchase price allocations were completed in the second quarter of 2020 for the Crius Transaction and the third quarter of 2020 for the Ambit Transaction.
Ambit Transaction and Crius Transactions Final Purchase Price Allocations
Ambit TransactionCrius Transaction
Final
Purchase Price
Allocation
Measurement Period Adjustments recorded through September 30, 2020Final
Purchase Price
Allocation
Measurement Period Adjustments recorded through June 30, 2020
Cash and cash equivalents$49 $— $26 $— 
Net working capital32 (9)(42)
Accumulated deferred income taxes— — — (36)
Identifiable intangible assets218 (45)317 23 
Goodwill258 44 243 38 
Commodity and other derivative contractual assets23 — 18 — 
Other noncurrent assets13 — 17 (3)
Total assets acquired593 612 (20)
Identifiable intangible liabilities— — (34)
Long-term debt, including amounts due currently— — 140 — 
Commodity and other derivative contractual liabilities28 — 40 — 
Accumulated deferred income taxes— — 14 14 
Other noncurrent liabilities and deferred credits10 16 — 
Total liabilities assumed38 212 (20)
Identifiable net assets acquired$555 $— $400 $— 

Acquisition costs incurred in the Ambit Transaction and Crius Transaction totaled $1 million and $2 million, respectively. For the Ambit Acquisition Date through December 31, 2019, our consolidated statements of operations include revenues and net income acquired in the Ambit Transaction totaling $193 million and $2 million, respectively. For the Crius Acquisition Date through December 31, 2019, our consolidated statements of operations include revenues and net income acquired in the Crius Transaction totaling $453 million and zero, respectively. The net income acquired in the Ambit Transaction and Crius Transaction include intangible amortization and transition related expenses.
Ambit and Crius Transaction Unaudited Pro Forma Financial Information — The following unaudited consolidated pro forma financial information for the years ended December 31, 2019 and 2018 assumes that the Ambit and Crius Transactions occurred on January 1, 2018 (i.e., represents our results for the years ended December 31, 2019 and 2018 plus the results for either Ambit Transaction or Crius Transaction for the period not owned by us, respectively). The unaudited consolidated pro forma financial information is provided for informational purposes only and is not necessarily indicative of the results of operations that would have occurred had the Ambit Transaction and Crius Transaction been completed on January 1, 2018, nor is the unaudited consolidated pro forma financial information indicative of future results of operations, which may differ materially from the consolidated pro forma financial information presented here.
Ambit TransactionCrius Transaction
Year Ended December 31,Year Ended December 31,
2019201820192018
Revenues$12,931 $10,446 $12,373 $10,379 
Net income (loss) (a)$949 $(95)$876 $(43)
Net income (loss) attributable to Vistra$951 $(93)$878 $(41)
Net income (loss) attributable to Vistra per weighted average share of common stock outstanding — basic$1.92 $(0.18)$1.78 $(0.08)
Net income (loss) attributable to Vistra per weighted average share of common stock outstanding — diluted$1.90 $(0.18)$1.76 $(0.08)
__________
(a)Decrease in pro forma net income compared to consolidated net income is driven by unrealized losses on hedging activities of Crius and amortization of intangible assets.

The consolidated unaudited pro forma financial information presented above includes adjustments for incremental depreciation and amortization as a result of the fair value determination of the net assets acquired and the related impacts on tax expense.

Dynegy Merger Transaction

On the Merger Date, Vistra and Dynegy completed the transactions contemplated by the Merger Agreement. Pursuant to the Merger Agreement, Dynegy merged with and into Vistra, with Vistra continuing as the surviving corporation. The Merger was intended to qualify as a tax-free reorganization under the IRC, so that none of Vistra, Dynegy or any of the Dynegy stockholders would recognize any gain or loss in the transaction, except that Dynegy stockholders could recognize a gain or loss with respect to cash received in lieu of fractional shares of Vistra's common stock. Vistra is the acquirer for both federal tax and accounting purposes.

On the Merger Date, each issued and outstanding share of Dynegy common stock, par value $0.01 per share, other than shares owned by Vistra or its subsidiaries, held in treasury by Dynegy or held by a subsidiary of Dynegy, was automatically converted into 0.652 shares of common stock, par value $0.01 per share, of Vistra (the Exchange Ratio), except that cash was paid in lieu of fractional shares, which resulted in Vistra issuing 94,409,573 shares of Vistra common stock to the former Dynegy stockholders, as well as converting stock options, equity-based awards, tangible equity units and warrants. The total number of Vistra shares outstanding at the close of the Merger was 522,932,453 shares. Dynegy stock options and equity-based awards outstanding immediately prior to the Merger Date were generally automatically converted upon completion of the Merger into stock options and equity-based awards, respectively, with respect to Vistra's common stock, after giving effect to the Exchange Ratio.

Dynegy Business Combination Accounting

We believe the Merger has provided and continues to provide significant strategic benefits and opportunities to Vistra, including increased scale and market diversification, rebalanced asset portfolio and improved earnings and cash flows. The Merger was accounted for in accordance with ASC 805, Business Combinations (ASC 805), with identifiable assets acquired and liabilities assumed recorded at their estimated fair values on the Merger Date. The combined results of operations are reported in our consolidated financial statements beginning as of the Merger Date. A summary of the techniques used to estimate the fair value of the identifiable assets and liabilities, as well as their classification within the fair value hierarchy (see Note 15), is listed below:

Working capital was valued using available market information (Level 2).
Acquired property, plant and equipment was valued using a combination of an income approach and a market approach. The income approach utilized a discounted cash flow analysis based upon a debt-free, free cash flow model (Level 3).
Acquired derivatives were valued using the methods described in Note 15 (Level 1, Level 2 or Level 3).
Contracts with terms that were not at current market prices were also valued using a discounted cash flow analysis (Level 3). The cash flows generated by the contracts were compared with their cash flows based on current market prices with the resulting difference discounted to present value and recorded as either an intangible asset or liability.
Long-term debt was valued using a market approach (Level 2).
AROs were recorded in accordance with ASC 410, Asset Retirement and Environmental Obligations (Level 3).

The following table summarizes the consideration paid and the final allocation of the purchase price to the fair value amounts recognized for the assets acquired and liabilities assumed related to the Merger as of the Merger Date. Based on the opening price of Vistra common stock on the Merger Date, the purchase price was approximately $2.3 billion. During the three months ended March 31, 2019, the purchase price allocation was completed. During the period from April 9, 2018 through March 31, 2019, we updated the initial purchase price allocation with final valuations by increasing property, plant and equipment by $173 million, decreasing intangible assets by $36 million, increasing goodwill by $175 million, decreasing accounts receivable, inventory, prepaid expenses and other current assets by $10 million, increasing accumulated deferred tax asset by $127 million, decreasing other noncurrent assets by $113 million, increasing trade accounts payable and other current liabilities by $89 million, increasing other noncurrent liabilities by $177 million, increasing asset retirement obligations, including amounts due currently by $56 million as well as other minor adjustments. The valuation revisions were a result of updated inputs used in determining the fair value of the acquired assets and liabilities.

Dynegy shares outstanding as of April 9, 2018 (in millions)144.8 
Exchange Ratio0.652 
Vistra shares issued for Dynegy shares outstanding (in millions)94.4 
Opening price of Vistra common stock on April 9, 2018$19.87 
Purchase price for common stock$1,876 
Fair value of equity component of tangible equity units369 
Fair value of outstanding stock compensation awards attributable to pre-combination service26 
Fair value of outstanding warrants
Total purchase price$2,273 


Dynegy Merger Final Purchase Price Allocation
Cash and cash equivalents$445 
Trade accounts receivables, inventories, prepaid expenses and other current assets853 
Property, plant and equipment10,535 
Accumulated deferred income taxes518 
Identifiable intangible assets351 
Goodwill175 
Other noncurrent assets419 
Total assets acquired13,296 
Trade accounts payable and other current liabilities733 
Commodity and other derivative contractual assets and liabilities, net422 
Asset retirement obligations, including amounts due currently475 
Long-term debt, including amounts due currently8,919 
Other noncurrent liabilities469 
Total liabilities assumed11,018 
Identifiable net assets acquired2,278 
Noncontrolling interest in subsidiary
Total purchase price$2,273 
Acquisition costs incurred in the Merger totaled less than $1 million and $25 million for the years ended December 31, 2019 and 2018, respectively. For the period from the Merger Date through December 31, 2018, our consolidated statements of operations include revenues and net income (loss) acquired in the Merger totaling $3.902 billion and $224 million respectively.

Dynegy Merger Unaudited Pro Forma Financial Information — The following unaudited pro forma financial information for the year ended December 31, 2018 assumes that the Merger occurred on January 1, 2018. The unaudited pro forma financial information is provided for informational purposes only and is not necessarily indicative of the results of operations that would have occurred had the Merger been completed on January 1, 2018, nor is the unaudited pro forma financial information indicative of future results of operations, which may differ materially from the pro forma financial information presented here.
Year Ended December 31, 2018
Revenues$10,595 
Net loss$(268)
Net loss attributable to Vistra$(265)
Net loss attributable to Vistra per weighted average share of common stock outstanding — basic$(0.52)
Net loss attributable to Vistra per weighted average share of common stock outstanding — diluted$(0.52)

The unaudited pro forma financial information presented above includes adjustments for incremental depreciation and amortization as a result of the fair value determination of the net assets acquired, interest expense on debt assumed in the Merger, effects of the Merger on tax expense (benefit), changes in the expected impacts of the tax receivable agreement due to the Merger, and other related adjustments.
v3.20.4
Acquisition and Development of Generation Facilities (Notes)
12 Months Ended
Dec. 31, 2020
Acquisition And Development Of Generation Facilities [Abstract]  
Acquisition and Development of Generation Facilities ACQUISITION AND DEVELOPMENT OF GENERATION FACILITIES
Texas Segment Solar Generation and Energy Storage Projects

In September 2020, we announced the planned development of up to 668 MW of solar photovoltaic power generation facilities and 260 MW of battery ESS in Texas. Estimated commercial operation dates for these facilities range from Summer 2021 to Fall 2022.

Upton 2 Phase I — In May 2017, we acquired the rights to develop, construct and operate a utility scale solar photovoltaic power generation facility in Upton County, Texas (Upton 2). As part of this project, we entered into a turnkey engineering, procurement and construction agreement to construct the approximately 180 MW facility. We spent approximately $231 million related to this project primarily for progress payments under the engineering, procurement and construction agreement and the acquisition of the development rights. The facility began test operations in March 2018 and commercial operations began in June 2018.

Upton 2 Phase II — In 2018, we completed the construction of our first battery energy storage system (ESS). In October 2018, we were awarded a $1 million grant from the TCEQ for our battery ESS at our Upton 2 solar facility. The grant is part of the Texas Emissions Reduction Plan. The 10 MW lithium-ion ESS captures excess solar energy produced during the day and releases the energy in late afternoon and early evening, when demand is highest. The Upton 2 Phase II battery ESS became operational in December 2018.

West Segment Energy Storage Projects

Oakland — In June 2019, East Bay Community Energy (EBCE) signed a ten-year contract to receive resource adequacy capacity from the planned development of a 20 MW battery ESS at our Oakland Power Plant site in California. In April 2020, the project received necessary approvals from EBCE and from Pacific Gas and Electric Company (PG&E). The contract was amended to increase the capacity of the planned development to a 36.25 MW battery ESS. In April 2020, the concurrent local area reliability service agreement to ensure grid reliability as part of the Oakland Clean Energy Initiative was signed and sent to the California Public Utilities Commission (CPUC) for approval, which is expected prior to the second quarter of 2021. The battery ESS project is expected to enter commercial operations by January 2022.

Moss Landing — In June 2018, we announced that, subject to approval by the CPUC, we would enter into a 20-year resource adequacy contract with PG&E to develop a 300 MW battery ESS at our Moss Landing Power Plant site in California (Moss Landing Phase I). PG&E filed its application with the CPUC in June 2018 and the CPUC approved the resource adequacy contract in November 2018. At December 31, 2020, we had accumulated approximately $370 million in construction work-in-process for Moss Landing Phase I. Under the contract, PG&E will pay us a fixed monthly resource adequacy payment, while we will receive the energy revenues and incur the costs from dispatching and charging the ESS. Moss Landing Phase I began test operations in December 2020 and is expected to be fully operational by April 2021. PG&E filed for Chapter 11 bankruptcy protection in January 2019. In November 2019, the bankruptcy court approved PG&E's motion requesting approval of the assumption of the resource adequacy contract subject to the CPUC approving the terms of an amendment to the resource adequacy contract, and the CPUC approved the terms of the amendment in January 2020. PG&E emerged from bankruptcy protection in July 2020.

In May 2020, we announced that, subject to approval by the CPUC, we would enter into a 10-year resource adequacy contract with PG&E to develop an additional 100 MW battery ESS at our Moss Landing Power Plant site (Moss Landing Phase II). PG&E filed its application with the CPUC in May 2020 and the CPUC approved the resource adequacy contract in August 2020. At December 31, 2020, we had accumulated approximately $29 million in construction work-in-process for Moss Landing Phase II. We anticipate Moss Landing Phase II will commence commercial operations in the third quarter of 2021.
v3.20.4
Retirement of Generation Facilities (Notes)
12 Months Ended
Dec. 31, 2020
Retirement of Generation Facilities [Abstract]  
Retirement of Generation Facilities RETIREMENT OF GENERATION FACILITIES
2020 Announcements

In December 2020, we announced our intention to retire two natural gas facilities in Texas due to their age, cost profile and small scale, as well as low power prices, limited operational windows and substantial costs to repair, maintain and upgrade the facilities.
NameLocationISO/RTOFuel TypeNet Generation Capacity (MW)Dates Units Retired or
Expected Retirement Date
WhartonBoling, TXERCOTNatural Gas83November 30, 2020
TrinidadTrinidad, TXERCOTNatural Gas244By April 30, 2021
Total327

In September 2020 and December 2020, we announced our intention to retire all of our remaining coal generation facilities in Illinois and Ohio, one coal generation facility in Texas and one natural gas facility in Illinois no later than year-end 2027 due to economic challenges, including incremental expenditures that would be required to comply with the CCR rule and ELG rule (see Note 13), and in furtherance of our efforts to significantly reduce our carbon footprint. Expected plant retirement expenses of $43 million, driven by severance cost, were accrued in the year ended December 31, 2020 in operating costs of our Sunset segment. Operational results for plants with planned retirements are included in our Sunset segment beginning in the quarter when a retirement plan is announced. See Note 21 for discussion of impairments recorded in connection with these announcements.
NameLocationISO/RTOFuel TypeNet Generation Capacity (MW)Expected Retirement Date (a)
BaldwinBaldwin, ILMISOCoal1,185By the end of 2025
Coleto CreekGoliad, TXERCOTCoal650By the end of 2027
JoppaJoppa, ILMISOCoal802By the end of 2025
JoppaJoppa, ILMISONatural Gas221By the end of 2025
KincaidKincaid, ILPJMCoal1,108By the end of 2027
Miami FortNorth Bend, OHPJMCoal1,020By the end of 2027
NewtonNewton, ILMISO/PJMCoal615By the end of 2027
ZimmerMoscow, OHPJMCoal1,300By the end of 2027
Total6,901
____________
(a)Generation facilities may retire earlier than expected dates if economic or other conditions dictate.

2019 Announcements

In September 2019, we announced the settlement of a lawsuit alleging violations of opacity and particulate matter limits at our Edwards facility in Bartonville, Illinois. As part of the settlement, which was approved by the U.S. District Court for the Central District of Illinois in November 2019, we will retire the Edwards facility by the end of 2022 (see Note 13). In August 2019, we announced the planned retirement of four additional power plants in Illinois with a total installed nameplate generation capacity of 2,068 MW. We retired these units due to changes in the Illinois multi-pollutant standard rule (MPS rule) that require us to retire approximately 2,000 MW of generation capacity (see Note 13). In light of the provisions of the Federal Power Act and the FERC regulations thereunder, the affected subsidiaries of Vistra identified the retired units by analyzing the economics of each of our Illinois plants and designating the least economic units for retirement. Expected plant retirement expenses of $47 million, driven by severance costs, were accrued in the year ended December 31, 2019 and were included primarily in operating costs of our Asset Closure segment. In August 2019, we remeasured our pension and OPEB plans resulting in an increase to the benefit obligation liability of $21 million, pretax other comprehensive loss of $18 million and curtailment expense of $3 million recognized as other deductions in our consolidated statements of operations. The following table details the units in Illinois totaling 2,653 MW that have been or will be retired. Operational results for the four retired plants identified below are included in the Asset Closure segment, which is engaged in the decommissioning and reclamation of retired plants and mines. Operational results for the Edwards facility are included in the Sunset segment.
NameLocationISO/RTOFuel TypeNet Generation Capacity (MW)Dates Units Retired or
Expected Retirement Date
CoffeenCoffeen, ILMISOCoal915 November 1, 2019
Duck CreekCanton, ILMISOCoal425 December 15, 2019
HavanaHavana, ILMISOCoal434 November 1, 2019
HennepinHennepin, ILMISOCoal294 November 1, 2019
EdwardsBartonville, ILMISOCoal585 By the end of 2022
Total2,653 

2018 Announcements

In August 2018, we filed a notice of suspension of operation with PJM and other mandatory regulatory notifications related to the retirement of our 51 MW Northeastern Power Company waste coal facility in McAdoo, Pennsylvania (Northeastern Facility). We decided to retire the Northeastern Facility due to its uneconomic operations and financial outlook. Following the receipt of regulatory approvals, the Northeastern Facility was retired in October 2018. The decision to retire the Northeastern Facility did not result in a material impact to the financial statements, and the operational results of the Northeastern Facility are included in our Asset Closure segment.

Two of our non-operated, jointly held power plants acquired in the Merger, for which our proportional generation capacity was 883 MW, were retired in May 2018. These units were retired as previously scheduled. No gain or loss was recorded in conjunction with the retirement of these units, and the operational results of these facilities are included in our Asset Closure segment. The following table details the units retired.
NameLocationISO/RTOFuel TypeNet Generation Capacity (MW)Ownership InterestDate Units Retired
KillenManchester, OhioPJMCoal204 33%May 31, 2018
StuartAberdeen, OhioPJMCoal679 39%May 24, 2018
Total
883 

In January and February 2018, we retired three power plants in Texas with a total installed nameplate generation capacity of 4,167 MW. We decided to retire these units because they were projected to be uneconomic based on then current market conditions and would have faced significant environmental costs associated with operating such units. In the case of the Sandow units, the decision also reflected the execution of a contract termination agreement pursuant to which the Company and Alcoa agreed to an early settlement of a long-standing power and mining agreement. Expected retirement expenses were accrued in the third and fourth quarter of 2017 and, as a result, no retirement expenses were recorded related to these facilities in the year ended December 31, 2018. The operational results of these facilities are included in our Asset Closure segment. The following table details the units retired.
NameLocation (all in the state of Texas)ISO/RTOFuel TypeInstalled Nameplate Generation Capacity (MW)Date Units Retired
MonticelloTitus CountyERCOTLignite/Coal1,880 January 4, 2018
SandowMilam CountyERCOTLignite1,137 January 11, 2018
Big BrownFreestone CountyERCOTLignite/Coal1,150 February 12, 2018
Total
4,167 
v3.20.4
Revenue (Notes)
12 Months Ended
Dec. 31, 2020
Revenue from Contract with Customer [Abstract]  
Revenue REVENUE
The following tables disaggregate our revenue by major source:
Year Ended December 31, 2020
RetailTexasEastWestSunsetAsset ClosureEliminationsConsolidated
Revenue from contracts with customers:
Retail energy charge in ERCOT$5,813 $— $— $— $— $— $— $5,813 
Retail energy charge in Northeast/Midwest2,406 — — — — — — 2,406 
Wholesale generation revenue from ISO/RTO— 475 310 124 473 — 1,383 
Capacity revenue from ISO/RTO (a)— — (52)— 164 — — 112 
Revenue from other wholesale contracts— 226 668 54 187 — 1,136 
Total revenue from contracts with customers8,219 701 926 178 824 — 10,850 
Other revenues:
Intangible amortization(5)— — (21)— — (24)
Hedging and other revenues (b)56 416 (108)101 151 — 617 
Affiliate sales— 2,999 1,595 298 — (4,895)— 
Total other revenues51 3,415 1,489 104 428 (4,895)593 
Total revenues$8,270 $4,116 $2,415 $282 $1,252 $$(4,895)$11,443 
____________
(a)Represents net capacity sold (purchased) in each ISO/RTO. The East segment includes net purchases of capacity in the PJM market and the Sunset segment includes net sales of capacity in the PJM market.
(b)Includes $164 million of unrealized net gains from mark-to-market valuations of commodity positions. See Note 20 for unrealized net gains (losses) by segment.


Year Ended December 31, 2019
RetailTexasEastWestSunsetAsset ClosureEliminationsConsolidated
Revenue from contracts with customers:
Retail energy charge in ERCOT$4,983 $— $— $— $— $— $— $4,983 
Retail energy charge in Northeast/Midwest1,818 — — — — — — 1,818 
Wholesale generation revenue from ISO/RTO— 1,477 629 193 751 194 — 3,244 
Capacity revenue from ISO/RTO— — 170 — 197 11 — 378 
Revenue from other wholesale contracts— 264 702 147 — 1,124 
Total revenue from contracts with customers6,801 1,741 1,501 202 1,095 207 — 11,547 
Other revenues:
Intangible amortization(15)— (4)(17)— — (32)
Hedging and other revenues (a)86 (250)37 132 247 42 — 294 
Affiliate sales— 2,345 1,256 — 277 92 (3,970)— 
Total other revenues71 2,095 1,289 136 507 134 (3,970)262 
Total revenues$6,872 $3,836 $2,790 $338 $1,602 $341 $(3,970)$11,809 
____________
(a)Includes $682 million of unrealized net gains from mark-to-market valuations of commodity positions. See Note 20 for unrealized net gains (losses) by segment.
Year Ended December 31, 2018
RetailTexasEastWestSunsetAsset ClosureEliminationsConsolidated
Revenue from contracts with customers:
Retail energy charge in ERCOT$4,426 $— $— $— $— $— $— $4,426 
Retail energy charge in Northeast/Midwest1,123 — — — — — — 1,123 
Wholesale generation revenue from ISO/RTO— 1,049 867 167 825 218 — 3,126 
Capacity revenue from ISO/RTO— — 376 30 258 34 — 698 
Revenue from other wholesale contracts— 214 67 137 — — 424 
Total revenue from contracts with customers5,549 1,263 1,310 203 1,220 252 — 9,797 
Other revenues:
Intangible amortization(26)(1)(9)— (7)— — (43)
Hedging and other revenues (a)74 (387)16 (214)(106)(610)
Affiliate sales— 1,622 578 — 184 225 (2,609)— 
Total other revenues48 1,234 585 (37)119 (2,607)(653)
Total revenues$5,597 $2,497 $1,895 $208 $1,183 $371 $(2,607)$9,144 
____________
(a)Includes $380 million of unrealized net losses from mark-to-market valuations of commodity positions. See Note 20 for unrealized net gains (losses) by segment.

Retail Energy Charges

Revenue is recognized when electricity is delivered to our customers in an amount that we expect to invoice for volumes delivered or services provided. Sales tax is excluded from revenue. Payment terms vary from 15 to 60 days from invoice date. Revenue is recognized over-time using the output method based on kilowatt hours delivered. Energy charges are delivered as a series of distinct services and are accounted for as a single performance obligation.

Energy sales and services that have been delivered but not billed by period end are estimated. Accrued unbilled revenues are based on estimates of customer usage since the date of the last meter reading provided by the independent system operators or electric distribution companies. Estimated amounts are adjusted when actual usage is known and billed.

As contracts for retail electricity can be for multi-year periods, the Company has performance obligations under these contracts that have not yet been satisfied. These performance obligations have transaction prices that are both fixed and variable, and that vary based on the contract duration and customer type. For the fixed price contracts, the amount of any unsatisfied performance obligations will vary based on customer usage, which will depend on factors such as weather and customer activity and therefore it is not practicable to estimate such amounts.

Wholesale Generation Revenue from ISOs/RTOs

Revenue is recognized when volumes are delivered to the ISO/RTO. Revenue is recognized over time using the output method based on kilowatt hours delivered and cash is settled within 10 days of invoicing. Vistra operates as a market participant within ERCOT, PJM, ISO-NE, NYISO, MISO and CAISO and expects to continue to remain under contract with each ISO/RTO indefinitely. Wholesale generation revenues are delivered as a series of distinct services and are accounted for as a single performance obligation. When electricity is sold to and purchased from the same ISO/RTO in the same period, the excess of the amount sold over the amount purchased is reflected in wholesale generation revenues.
Capacity Revenue From ISO/RTO

We offer generation capacity into competitive ISO/RTO auctions in exchange for revenue from awarded capacity offers. Capacity ensures installed generation and demand response is available to satisfy system integrity and reliability requirements. Capacity revenues are recognized when the performance obligation is satisfied ratably over time as our power generation facilities stand ready to deliver power to the customer. Penalties are assessed by the ISO/RTO against generation facilities if the facility is not available during the capacity period. The penalties are recorded as a reduction to revenue. When capacity is sold to and purchased from the same ISO/RTO in the same period, the excess of the amount sold over the amount purchased is reflected in capacity revenue.

Revenue from Other Wholesale Contracts

Other wholesale contracts include other revenue activity with the ISO/RTO, such as ancillary services, auction revenue, neutrality revenue and revenue from nonaffiliated retail electric providers, municipalities or other wholesale counterparties. Revenue is recognized when the service is performed. Revenue is recognized over time using the output method based on kilowatt hours delivered or other applicable measurements, and cash settles shortly after invoicing. Vistra operates as a market participant within ERCOT, PJM, ISO-NE, NYISO, MISO and CAISO and expects to continue to remain under contract with each ISO/RTO indefinitely. Other wholesale contracts are delivered as a series of distinct services and are accounted for as a single performance obligation.

Other Revenues

Some of our contracts for the sale of electricity meet the definition of a derivative under the accounting standards related to derivative instruments. Revenue from derivative contracts is not considered revenue from contracts with customers under the accounting standards related to revenue. Our revenue from the sale of electricity under derivative contracts, including the impact of unrealized gains or losses on those contracts, is reported in the table above as hedging and other revenues. We have classified all sales to affiliates that are eliminated in consolidation as other revenues in the table above.

Contract and Other Customer Acquisition Costs

We defer costs to acquire retail contracts and amortize these costs over the expected life of the contract. The expected life of a retail contract is calculated using historical attrition rates, which we believe to be an accurate indicator of future attrition rates. The deferred acquisition and contract cost balance as of December 31, 2020, 2019 and 2018 and January 1, 2018 was $80 million, $53 million, $38 million and $22 million, respectively. The amortization related to these costs during the year ended December 31, 2020 and 2019 totaled $46 million and $21 million, respectively, recorded as SG&A expenses, and $7 million and $9 million, respectively, recorded as a reduction to operating revenues in the consolidated statements of operations.

Practical Expedients

The vast majority of revenues are recognized under the right to invoice practical expedient, which allows us to recognize revenue in the same amount that we have a right to invoice our customers. Unbilled revenues are recorded based on the volumes delivered and services provided to the customers at the end of the period, using the right to invoice practical expedient. We have elected to not disclose the value of unsatisfied performance obligations for contracts with variable consideration for which we recognize revenue using the right to invoice practical expedient. We use the portfolio approach in evaluating similar customer contracts with similar performance obligations. Sales taxes are not included in revenue.

Performance Obligations

As of December 31, 2020, we have future performance obligations that are unsatisfied, or partially unsatisfied, relating to capacity auction volumes awarded through capacity auctions held by the ISO/RTO or contracts with customers. Therefore, an obligation exists as of the date of the results of the respective ISO/RTO capacity auction or the contract execution date. These obligations total $834 million, $496 million, $121 million, $38 million and $12 million that will be recognized in the years ending December 31, 2021, 2022, 2023, 2024 and 2025, respectively, and $7 million thereafter. Capacity revenues are recognized as capacity is made available to the related ISOs/RTOs or counterparties.
Accounts Receivable

The following table presents trade accounts receivable (net of allowance for uncollectible accounts) relating to both contracts with customers and other activities:
December 31,
20202019
Trade accounts receivable from contracts with customers — net$1,169 $1,246 
Other trade accounts receivable — net110 119 
Total trade accounts receivable — net$1,279 $1,365 
v3.20.4
Goodwill and Identifiable Intangible Assets and Liabilities (Notes)
12 Months Ended
Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Identifiable Intangible Assets and Liabilities GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS AND LIABILITIES
Goodwill

The following table provides information regarding our goodwill balance. There have been no impairments of goodwill since Emergence.

Balance at December 31, 2018$2,068 
Measurement period adjustments recorded in connection with the Merger14 
Goodwill recorded in connection with the Crius Transaction257 
Goodwill recorded in connection with the Ambit Transaction214 
Balance at December 31, 20192,553 
Measurement period adjustments recorded in connection with the Crius Transaction(14)
Measurement period adjustments recorded in connection with the Ambit Transaction44 
Balance at December 31, 2020$2,583 

At December 31, 2020, the goodwill balance of $2.583 billion consisted of the following:

$1.907 billion arose in connection with our application of fresh start reporting at Emergence and was allocated entirely to our Retail reporting unit. Of the goodwill recorded at Emergence, $1.686 billion is deductible for tax purposes over 15 years on a straight-line basis.
$175 million arose in connection with the Merger, of which $122 million was allocated to our Texas Generation reporting unit and $53 million was allocated to our Retail reporting unit. None of the goodwill related to the Merger is deductible for tax purposes.
$243 million of goodwill arose in connection with the Crius Transaction and was allocated entirely to our Retail reporting unit. None of the goodwill related to the Crius Transaction is deductible for tax purposes.
$258 million of goodwill arose in connection with the Ambit Transaction and was allocated entirely to our Retail reporting unit. The goodwill related to the Ambit Transaction is deductible for tax purposes over 15 years on a straight-line basis.

Goodwill and intangible assets with indefinite useful lives are required to be evaluated for impairment at least annually or whenever events or changes in circumstances indicate an impairment may exist. We have selected October 1 as our annual goodwill test date. On the most recent goodwill testing date, we applied qualitative factors and determined that it was more likely than not that the fair value of our Retail and Texas Generation reporting units exceeded their carrying value at October 1, 2020. Significant qualitative factors evaluated included reporting unit financial performance and market multiples, cost factors, customer attrition and changes in reporting unit book value.
Identifiable Intangible Assets and Liabilities

Identifiable intangible assets are comprised of the following:
December 31, 2020December 31, 2019
Identifiable Intangible AssetGross
Carrying
Amount
Accumulated
Amortization
NetGross
Carrying
Amount
Accumulated
Amortization
Net
Retail customer relationship$2,082 $1,434 $648 $2,078 $1,151 $927 
Software and other technology-related assets414 186 228 341 125 216 
Retail and wholesale contracts272 204 68 315 182 133 
Contractual service agreements (a)51 50 59 54 
Other identifiable intangible assets (b)96 19 77 40 15 25 
Total identifiable intangible assets subject to amortization$2,915 $1,844 1,071 $2,833 $1,478 1,355 
Retail trade names (not subject to amortization)1,374 1,391 
Mineral interests (not currently subject to amortization)
Total identifiable intangible assets$2,446 $2,748 
____________
(a)At December 31, 2020, amounts related to contractual service agreements that have become liabilities due to amortization of the economic impacts of the intangibles have been removed from both the gross carrying amount and accumulated amortization.
(b)Includes mining development costs and environmental allowances (emissions allowances and renewable energy certificates).

Identifiable intangible liabilities are comprised of the following:
Year Ended December 31,
Identifiable Intangible Liability20202019
Contractual service agreements
$129 $110 
Purchase and sale of power and capacity
87 100 
Fuel and transportation purchase contracts73 76 
Total identifiable intangible liabilities$289 $286 
Expense related to finite-lived identifiable intangible assets and liabilities (including the classification in the consolidated statements of operations) consisted of:
Identifiable Intangible Assets and LiabilitiesConsolidated Statements of OperationsRemaining useful lives of identifiable intangible assets at December 31,
2020 (weighted average in years)
Year Ended December 31,
202020192018
Retail customer relationshipDepreciation and amortization3$283 $275 $304 
Software and other technology-related assetsDepreciation and amortization473 61 62 
Retail and wholesale contracts/purchase and sale/fuel and transportation contractsOperating revenues/fuel, purchased power costs and delivery fees317 23 43 
Other identifiable intangible assetsOperating revenues/fuel, purchased power costs and delivery fees/depreciation and amortization5223 148 58 
Total intangible asset expense (a)$596 $507 $467 
____________
(a)Amounts recorded in depreciation and amortization totaled $360 million, $340 million and $370 million for the years ended December 31, 2020, 2019 and 2018 respectively. Amounts exclude contractual services agreements. Amounts include all expenses associated with environmental allowances including expenses accrued to comply with emissions allowance programs and renewable portfolio standards which are presented in fuel, purchased power costs and delivery fees on our consolidated statements of operations. Emissions allowance obligations are accrued as associated electricity is generated and renewable energy certificate obligations are accrued as retail electricity delivery occurs.

The following is a description of the separately identifiable intangible assets. In connection with fresh start reporting, the Merger, the Crius Transaction and the Ambit Transaction, the intangible assets were adjusted based on their estimated fair value as of the Effective Date, the Merger Date, the Crius Acquisition Date and the Ambit Acquisition Date, respectively, based on observable prices or estimates of fair value using valuation models.

Retail customer relationship — Retail customer relationship intangible asset represents the fair value of our non-contracted retail customer base, including residential and business customers, and is being amortized using an accelerated method based on historical customer attrition rates and reflecting the expected pattern in which economic benefits are realized over their estimated useful life.

Retail trade names — Our retail trade name intangible asset represents the fair value of our retail brands, including the trade names of TXU EnergyTM, Ambit Energy, 4Change EnergyTM, Homefield Energy, Dynegy Energy Services, TriEagle Energy, Public Power and U.S. Gas & Electric, and was determined to be an indefinite-lived asset not subject to amortization. This intangible asset is evaluated for impairment at least annually in accordance with accounting guidance related to goodwill and other indefinite-lived intangible assets. Significant assumptions included within the development of the fair value estimate include estimated gross margins for future periods and implied royalty rates. On the most recent testing date, we determined that it was more likely than not that the fair value of our retail trade name intangible asset exceeded its carrying value at October 1, 2020.

Retail and wholesale contracts/purchase and sale contracts — These intangible assets represent the value of various retail and wholesale contracts and purchase and sale contracts. The contracts were identified as either assets or liabilities based on the respective fair values as of the Effective Date, the Merger Date, the Crius Acquisition Date or the Ambit Acquisition Date utilizing prevailing market prices for commodities or services compared to the fixed prices contained in these agreements. The intangible assets or liabilities are being amortized in relation to the economic terms of the related contracts.
Contractual service agreements — Our acquired contractual service agreements represent the estimated fair value of favorable or unfavorable contract obligations with respect to long-term plant maintenance agreements, rail transportation agreements and rail car leases, and are being amortized based on the expected usage of the service agreements over the contract terms. The majority of the plant maintenance services relate to capital improvements and the related amortization of the plant maintenance agreements is recorded to property, plant and equipment. Amortization of rail transportation and rail car lease agreements is recorded to fuel, purchased power costs and delivery fees.

Estimated Amortization of Identifiable Intangible Assets and Liabilities

As of December 31, 2020, the estimated aggregate amortization expense of identifiable intangible assets and liabilities for each of the next five fiscal years is as shown below.
YearEstimated Amortization Expense
2021$276 
2022$183 
2023$128 
2024$78 
2025$54 
v3.20.4
Income Taxes
12 Months Ended
Dec. 31, 2020
Income Tax Disclosure [Abstract]  
Income Taxes INCOME TAXES
Vistra files a U.S. federal income tax return that includes the results of its consolidated subsidiaries. Vistra is the corporate parent of the Vistra consolidated group. Pursuant to applicable U.S. Department of the Treasury regulations and published guidance of the IRS, corporations that are members of a consolidated group have joint and several liability for the taxes of such group.

Income Tax Expense (Benefit)

The components of our income tax expense (benefit) are as follows:
Year Ended December 31,
202020192018
Current:
U.S. Federal$(5)$(1)$(13)
State41 10 30 
Total current36 17 
Deferred:
U.S. Federal171 260 (8)
State59 21 (54)
Total deferred230 281 (62)
Total$266 $290 $(45)
Reconciliation of income taxes computed at the U.S. federal statutory rate to income tax expense (benefit) recorded:
Year Ended December 31,
202020192018
Income (loss) before income taxes$890 $1,216 $(101)
U.S. federal statutory rate21 %21 %21 %
Income taxes at the U.S. federal statutory rate187 255 (20)
Nondeductible TRA accretion(7)
State tax, net of federal benefit32 48 22 
Federal and State return to provision adjustment13 (17)(12)
Remeasurement of historical Vistra deferred taxes for expanded state footprint— — (54)
Effect of refundable minimum tax credits no longer subject to sequestration— — (15)
Nondeductible compensation— 
Nondeductible transaction costs— 
Equity awards— (4)(3)
Valuation allowance on state NOLs41 13 20 
Lignite depletion(3)(6)— 
Texas gross margin amended return— (3)— 
Other(6)(2)
Income tax expense (benefit)$266 $290 $(45)
Effective tax rate29.9 %23.8 %44.6 %

Deferred Income Tax Balances

Deferred income taxes provided for temporary differences based on tax laws in effect at December 31, 2020 and 2019 are as follows:
December 31,
20202019
Noncurrent Deferred Income Tax Assets
Tax credit carryforwards$75 $73 
Loss carryforwards953 921 
Identifiable intangible assets293 214 
Long-term debt19 257 
Employee benefit obligations129 112 
Commodity contracts and interest rate swaps96 108 
Other47 43 
Total deferred tax assets$1,612 $1,728 
Noncurrent Deferred Income Tax Liabilities
Property, plant and equipment632 554 
Total deferred tax liabilities632 554 
Valuation allowance143 110 
Net Deferred Income Tax Asset$837 $1,064 
At December 31, 2020, we had total deferred tax assets of approximately $837 million that were substantially comprised of book and tax basis differences related to our generation and mining property, plant and equipment, as well as federal and state net operating loss (NOL) carryforwards. Our deferred tax assets were significantly impacted by the Merger. For the year ended December 31, 2020, we recognized a partial valuation allowance of $32 million on the net operating loss carryforwards related largely to Illinois and New York due to forecasted expiration. As of December 31, 2019, we assessed the need for a valuation allowance related to our deferred tax asset and considered both positive and negative evidence related to the likelihood of realization of the deferred tax assets. In connection with our analysis, we concluded that it is more likely than not that the federal deferred tax assets will be fully utilized by future taxable income, and thus no valuation allowance was required.

At December 31, 2020, we had $3.4 billion pre-tax net operating loss (NOL) carryforwards for federal income tax purposes that will begin to expire in 2032. At December 31, 2020, we had no remaining AMT credits refundable through the TCJA available.

The income tax effects of the components included in accumulated other comprehensive income totaled a net deferred tax asset of $5 million and $3 million at December 31, 2020 and 2019, respectively.

Coronavirus Aid, Relief, and Economic Security Act (CARES Act) and Final Section 163(j) Regulations

In response to the global pandemic related to COVID-19, the CARES Act was signed into law in March 2020. The CARES Act provides numerous relief provisions for corporate taxpayers, including modification of the utilization limitations on net operating losses, favorable expansion of the deduction for business interest expense under IRC Section 163(j) (Section 163(j)), the ability to accelerate timing of refundable AMT credits and the temporary suspension of certain payment requirements for the employer portion of social security taxes. Additionally, the final Section 163(j) regulations were issued in July 2020 and provided a critical correction to the proposed regulations with respect to the computation of adjusted taxable income. Vistra received $64 million in 2020 relating to the acceleration of AMT refunds and an approximate $350 million increase in interest expense deduction over the 2019 and 2020 tax years under the cumulative impact of these final laws and regulation pertaining to Section 163(j). Additionally, Vistra expects to receive an approximate $305 million increase in interest expense deduction in the 2021 tax year under the final Section 163(j) regulations. We do not anticipate a material impact to the effective tax rate from these impacts. Vistra is also utilizing the CARES Act payroll deferral mechanism to defer the payment of approximately $22 million from 2020 to 2021 and 2022.

Liability for Uncertain Tax Positions

Accounting guidance related to uncertain tax positions requires that all tax positions subject to uncertainty be reviewed and assessed with recognition and measurement of the tax benefit based on a "more-likely-than-not" standard with respect to the ultimate outcome, regardless of whether this assessment is favorable or unfavorable.

We classify interest and penalties related to uncertain tax positions as current income tax expense. The amounts were immaterial for the years ended December 31, 2020, 2019 and 2018. The following table summarizes the changes to the uncertain tax positions, reported in accumulated deferred income taxes and other current liabilities in the consolidated balance sheets for the years ended December 31, 2020, 2019 and 2018.
Year Ended December 31,
202020192018
Balance at beginning of period, excluding interest and penalties$126 $39 $— 
Additions allocated in the Merger— — 39 
Additions based on tax positions related to prior years— 
Reductions based on tax positions related to prior years(90)— — 
Additions based on tax positions related to the current year— 87 — 
Settlements with taxing authorities— (3)— 
Balance at end of period, excluding interest and penalties$39 $126 $39 
Vistra and its subsidiaries file income tax returns in U.S. federal and state jurisdictions and are expected to be subject to examinations by the IRS and other taxing authorities. The IRS has notified us of its intention to open an audit regarding the 2018 tax year. Crius is currently under audit by the IRS for the tax years 2015 and 2016. Uncertain tax positions totaling $39 million at December 31, 2020 reflect the final regulations under Section 163(j) that were released in July 2020, and we have adjusted deferred tax assets and liabilities by $87 million in the year ended December 31, 2020. Uncertain tax positions totaling $39 million at December 31, 2018 arose in connection with the Merger as discussed in Note 2.

Tax Matters Agreement

On the Effective Date, we entered into the Tax Matters Agreement with EFH Corp. whereby the parties have agreed to take certain actions and refrain from taking certain actions in order to preserve the intended tax treatment of the Spin-Off and to indemnify the other parties to the extent a breach of such agreement results in additional taxes to the other parties.

Among other things, the Tax Matters Agreement allocates the responsibility for taxes for periods prior to the Spin-Off between EFH Corp. and us. For periods prior to the Spin-Off: (a) Vistra is generally required to reimburse EFH Corp. with respect to any taxes paid by EFH Corp. that are attributable to us and (b) EFH Corp. is generally required to reimburse us with respect to any taxes paid by us that are attributable to EFH Corp.

We are also required to indemnify EFH Corp. against taxes, under certain circumstance, if the IRS or another taxing authority successfully challenges the amount of gain relating to the PrefCo Preferred Stock Sale or the amount or allowance of EFH Corp.'s net operating loss deductions.

Subject to certain exceptions, the Tax Matters Agreement prohibits us from taking certain actions that could reasonably be expected to undermine the intended tax treatment of the Spin-Off or to jeopardize the conclusions of the private letter ruling we obtained from the IRS or opinions of counsel received by us or EFH Corp., in each case, in connection with the Spin-Off. Certain of these restrictions apply for two years after the Spin-Off.

Under the Tax Matters Agreement, we may engage in an otherwise restricted action if (a) we obtain written consent from EFH Corp., (b) such action or transaction is described in or otherwise consistent with the facts in the private letter ruling we obtained from the IRS in connection with the Spin-Off, (c) we obtain a supplemental private letter ruling from the IRS, or (d) we obtain an unqualified opinion of a nationally recognized law or accounting firm that is reasonably acceptable to EFH Corp. that the action will not affect the intended tax treatment of the Spin-Off.
v3.20.4
Tax Receivable Agreement Obligation (Notes)
12 Months Ended
Dec. 31, 2020
Income Tax Disclosure [Abstract]  
Tax Receivable Agreement Obligation TAX RECEIVABLE AGREEMENT OBLIGATION
On the Effective Date, Vistra entered into a tax receivable agreement (the TRA) with a transfer agent on behalf of certain former first-lien creditors of TCEH. The TRA generally provides for the payment by us to holders of TRA Rights of 85% of the amount of cash savings, if any, in U.S. federal and state income tax that we realize in periods after Emergence as a result of (a) certain transactions consummated pursuant to the Plan of Reorganization (including the step-up in tax basis in our assets resulting from the PrefCo Preferred Stock Sale), (b) the tax basis of all assets acquired in connection with the acquisition of two CCGT natural gas-fueled generation facilities in April 2016 and (c) tax benefits related to imputed interest deemed to be paid by us as a result of payments under the TRA, plus interest accruing from the due date of the applicable tax return.

Pursuant to the TRA, we issued the TRA Rights for the benefit of the first lien secured creditors of TCEH entitled to receive such TRA Rights under the Plan of Reorganization. Such TRA Rights are entitled to certain registration rights more fully described in the Registration Rights Agreement (see Note 19).
The following table summarizes the changes to the TRA obligation, reported as other current liabilities and Tax Receivable Agreement obligation in our consolidated balance sheets, for the years ended December 31, 2020, 2019 and 2018.
Year Ended December 31,
202020192018
TRA obligation at the beginning of the period$455 $420 $357 
Accretion expense64 59 65 
Changes in tax assumptions impacting timing of payments (a)(69)(22)14 
Impacts of Tax Receivable Agreement(5)37 79 
Payments— (2)(16)
TRA obligation at the end of the period450 455 420 
Less amounts due currently(3)— — 
Noncurrent TRA obligation at the end of the period$447 $455 $420 
____________
(a)During the year ended December 31, 2020, we recorded a decrease to the carrying value of the TRA obligation totaling $69 million as a result of adjustments to forecasted taxable income, including the impacts of the CARES Act, changes to Section 163(j) percentage limitation amount, the impacts from the issuance of the final Section 163(j) regulations and the anticipated tax benefits from renewable development projects. During the year ended December 31, 2019, we recorded a decrease to the carrying value of the TRA obligation totaling approximately $22 million as a result of adjustments to the timing of forecasted taxable income and state apportionment due to the expansion of Vistra's state income tax profile, including the Dynegy, Crius and Ambit acquisitions. During the year ended December 31, 2018, we recorded an increase to the carrying value of the TRA obligation totaling $14 million related to changes in the timing of estimated payments resulting changes in the timing of estimated payments and new multistate tax impacts resulting from the Merger.

As of December 31, 2020, the estimated carrying value of the TRA obligation totaled $450 million, which represents the discounted amount of projected payments under the TRA. The projected payments are based on certain assumptions, including but not limited to (a) the federal corporate income tax rate of 21%, (b) estimates of our taxable income in the current and future years and (c) additional states that Vistra now operates in, including the relevant tax rate and apportionment factor for each state. Our taxable income takes into consideration the current federal tax code, various relevant state tax laws and reflects our current estimates of future results of the business. These assumptions are subject to change, and those changes could have a material impact on the carrying value of the TRA obligation. As of December 31, 2020, the aggregate amount of undiscounted federal and state payments under the TRA is estimated to be approximately $1.4 billion, with more than half of such amount expected to be paid during the next 15 years, and the final payment expected to be made around the year 2056 (if the TRA is not terminated earlier pursuant to its terms).

The carrying value of the obligation is being accreted to the amount of the gross expected obligation using the effective interest method. Changes in the amount of this obligation resulting from changes to either the timing or amount of TRA payments are recognized in the period of change and measured using the discount rate inherent in the initial fair value of the obligation.
v3.20.4
Earnings Per Share (Notes)
12 Months Ended
Dec. 31, 2020
Earnings Per Share [Abstract]  
Earnings Per Share EARNINGS PER SHARE
Basic earnings per share available to common stockholders are based on the weighted average number of common shares outstanding during the period. Diluted earnings per share is calculated using the treasury stock method and includes the effect of all potential issuances of common shares under stock-based incentive compensation arrangements.
Year Ended December 31,
202020192018
Net income (loss) attributable to common stock — basic$636 $928 $(54)
Weighted average shares of common stock outstanding — basic488,668,263 494,146,268 504,954,371 
Net income (loss) per weighted average share of common stock outstanding — basic$1.30 $1.88 $(0.11)
Dilutive securities: Stock-based incentive compensation plan2,422,205 5,789,223 — 
Weighted average shares of common stock outstanding — diluted491,090,468 499,935,490 504,954,371 
Net income (loss) per weighted average share of common stock outstanding — diluted$1.30 $1.86 $(0.11)
Stock-based incentive compensation plan awards excluded from the calculation of diluted earnings per share because the effect would have been antidilutive totaled 12,553,414, 2,447,850 and 14,165,813 shares for the years ended December 31, 2020, 2019 and 2018, respectively.
v3.20.4
Accounts Receivable Financing (Notes)
12 Months Ended
Dec. 31, 2020
Accounts Receivable Financing [Abstract]  
Accounts Receivable Financing ACCOUNTS RECEIVABLE FINANCING
Accounts Receivable Securitization Program

TXU Energy Receivables Company LLC (RecCo), an indirect subsidiary of Vistra, has an accounts receivable financing facility (Receivables Facility) provided by issuers of asset-backed commercial paper and commercial banks (Purchasers). The Receivables Facility was renewed in July 2020, extending the term of the Receivables Facility to July 2021, with the ability to borrow $550 million beginning with the settlement date in July 2020 until the settlement date in August 2020, $625 million from the settlement date in August 2020 until the settlement date in November 2020, $550 million from the settlement date in November 2020 until the settlement date in December 2020 and $450 million thereafter for the remaining term of the Receivables Facility. In December 2020, the Receivables Facility was amended to include Ambit Texas, LLC (Ambit Texas), Value Based Brands and TriEagle Energy, as originators, and increase the commitment of the Purchasers to $500 million for the remaining term of the Receivables Facility. In February 2021, the Receivables Facility was amended to allow for a one-time, $596 million borrowing to take advantage of a higher receivable balance at such time. The borrowing limit is expected to return to $500 million in March 2021.

In connection with the Receivables Facility, TXU Energy, Dynegy Energy Services, Ambit Texas, Value Based Brands and TriEagle Energy, each indirect subsidiaries of Vistra and originators under the Receivables Facility (Originators), each sell and/or contribute, subject to certain exclusions, all of its receivables (other than any receivables excluded pursuant to the terms of the Receivables Facility), arising from the sale of electricity to its customers and related rights (Receivables), to RecCo, a consolidated, wholly owned, bankruptcy-remote, direct subsidiary of TXU Energy. RecCo, in turn, is subject to certain conditions, and may draw under the Receivables Facility up to the limits described above to fund its acquisition of the Receivables from the Originators. RecCo has granted a security interest on the Receivables and all related assets for the benefit of the Purchasers under the Receivables Facility and Vistra Operations has agreed to guarantee the obligations under the agreements governing the Receivables Facility. Amounts funded by the Purchasers to RecCo are reflected as short-term borrowings on the consolidated balance sheets. Proceeds and repayments under the Receivables Facility are reflected as cash flows from financing activities in our consolidated statements of cash flows. Receivables transferred to the Purchasers remain on Vistra's balance sheet and Vistra reflects a liability equal to the amount advanced by the Purchasers. The Company records interest expense on amounts advanced. TXU Energy continues to service, administer and collect the Receivables on behalf of RecCo and the Purchasers, as applicable.

As of December 31, 2020, outstanding borrowings under the receivables facility totaled $300 million and were supported by $735 million of RecCo gross receivables. As of December 31, 2019, outstanding borrowings under the Receivables Facility totaled $450 million and were supported by $629 million of RecCo gross receivables. As of February 23, 2021, outstanding borrowings under the receivables facility totaled approximately $596 million and were supported by approximately $774 million of RecCo gross receivables..

Repurchase Facility

In October 2020, TXU Energy and the other originators under the Receivables Facility entered into a $125 million repurchase facility (Repurchase Facility) that is provided on an uncommitted basis by a commercial bank as buyer (Buyer). The Repurchase Facility is collateralized by a subordinated note (Subordinated Note) issued by RecCo in favor of TXU Energy for the benefit of Originators under the Receivables Facility and representing a portion of the outstanding balance of the purchase price paid for the Receivables sold by the Originators to RecCo under the Receivables Facility. Under the Repurchase Facility, TXU Energy may request that Buyer transfer funds to TXU Energy in exchange for a transfer of the Subordinated Note, with a simultaneous agreement by TXU Energy to transfer funds to Buyer at a date certain or on demand in exchange for the return of the Subordinated Note (collectively, the Transactions). Each Transaction is expected to have a term of one month, unless terminated earlier on demand by TXU Energy or terminated by Buyer after an event of default.

TXU Energy and the other Originators have each granted Buyer a first-priority security interest in the Subordinated Note to secure its obligations under the agreements governing the Repurchase Facility, and Vistra Operations has agreed to guarantee the obligations under the agreements governing the Repurchase Facility. Unless earlier terminated under the agreements governing the Repurchase Facility, the Repurchase Facility will terminate concurrently with the schedule termination of the Receivables Facility.
As of December 31, 2020, there were no borrowings under the Repurchase Facility. In February 2021, the Company borrowed $125 million under the Repurchase Facility.
v3.20.4
Long-Term Debt
12 Months Ended
Dec. 31, 2020
Debt Disclosure [Abstract]  
Long-Term Debt LONG-TERM DEBT
Amounts in the table below represent the categories of long-term debt obligations incurred by the Company.
December 31,
20202019
Vistra Operations Credit Facilities$2,572 $2,700 
Vistra Operations Senior Secured Notes:
3.550% Senior Secured Notes, due July 15, 2024
1,500 1,500 
3.700% Senior Secured Notes, due January 30, 2027
800 800 
4.300% Senior Secured Notes, due July 15, 2029
800 800 
Total Vistra Operations Senior Secured Notes3,100 3,100 
Vistra Operations Senior Unsecured Notes:
5.500% Senior Unsecured Notes, due September 1, 2026
1,000 1,000 
5.625% Senior Unsecured Notes, due February 15, 2027
1,300 1,300 
5.000% Senior Unsecured Notes, due July 31, 2027
1,300 1,300 
Total Vistra Operations Senior Unsecured Notes3,600 3,600 
Vistra Senior Unsecured Notes:
5.875% Senior Unsecured Notes, due June 1, 2023
— 500 
8.000% Senior Unsecured Notes, due January 15, 2025
— 81 
8.125% Senior Unsecured Notes, due January 30, 2026
— 166 
Total Vistra Senior Unsecured Notes— 747 
Other:
Forward Capacity Agreements45 161 
Equipment Financing Agreements68 99 
8.82% Building Financing due semiannually through February 11, 2022 (a)
10 15 
Other12 
Total other long-term debt126 287 
Unamortized debt premiums, discounts and issuance costs (b)(68)(55)
Total long-term debt including amounts due currently9,330 10,379 
Less amounts due currently(95)(277)
Total long-term debt less amounts due currently$9,235 $10,102 
____________
(a)Obligation related to a corporate office space finance lease. This obligation will be funded by amounts held in an escrow account that is reflected in other noncurrent assets in our consolidated balance sheets.
(b)Includes impact of recording debt assumed in the Merger at fair value.

Vistra Operations Credit Facilities

At December 31, 2020, the Vistra Operations Credit Facilities consisted of up to $5.297 billion in senior secured, first-lien revolving credit commitments and outstanding term loans, which consisted of revolving credit commitments of up to $2.725 billion, including a $2.35 billion letter of credit sub-facility (Revolving Credit Facility) and term loans of $2.572 billion (Term Loan B-3 Facility). These amounts reflect the following transactions and amendments completed in 2020, 2019 and 2018:

In March 2020, Vistra Operations repurchased $100 million principal amount of Term Loan B-3 Facility borrowings at a weighted average price of $93.875 and cancelled them. We recorded an extinguishment gain of $6 million on the transaction in the year ended December 31, 2020.
In November 2019, Vistra Operations used the net proceeds from the November 2019 Senior Secured Notes Offering described below and $799 million of incremental borrowings under the Term Loan B-3 Facility to repay the entire amount outstanding of $1.897 billion of term loans under the B-1 Facility (Term Loan B-1 Facility). Fees and expenses related to the transactions totaled $2 million in the year ended December 31, 2019, which were recorded as interest expense and other charges on the consolidated statements of operations.

In October 2019, Vistra Operations borrowed $550 million under the Revolving Credit Facility. The proceeds of the borrowings were used for general corporate purposes, including the funding of a $425 million dividend to Vistra to pay the principal, premium and interest due in connection with the redemption by Vistra of the entire $387 million aggregate principal amount outstanding of 7.625% senior notes described below. In November 2019, Vistra Operations repaid $200 million under the Revolving Credit Facility.

In June 2019, Vistra Operations used the net proceeds from the June 2019 Senior Secured Notes Offerings (described below) to repay $889 million under the Term Loan B-1 Facility, the entire amount outstanding of $977 million of term loans under the B-2 Facility (Term Loan B-2 Facility, and together with the Term Loan B-1 Facility and the Term Loan B-3 Facility, the Term Loan B Facility) and $134 million under the Term Loan B-3 Facility. We recorded an extinguishment loss of $4 million on the transactions in the year ended December 31, 2019.

In March 2019 and May 2019, the Vistra Operations Credit Facilities were amended whereby we obtained $225 million of incremental Revolving Credit Facility commitments. The letter of credit sub-facility was also increased by $50 million. Fees and expenses related to the amendments to the Vistra Operations Credit Facilities totaled $2 million for the year ended December 31, 2019, which were capitalized as a noncurrent asset.

In June 2018, the Vistra Operations Credit Facilities were amended whereby we incurred $2.050 billion of borrowings under the new Term Loan B-3 Facility and obtained $1.640 billion of incremental Revolving Credit Facility commitments. The letter of credit sub-facility was also increased by $1.585 billion. The maturity date of the Revolving Credit Facility was extended from August 4, 2021 to June 14, 2023. As discussed below, the proceeds from the Term Loan B-3 Facility were used to repay borrowings under the credit agreement that Vistra assumed from Dynegy in connection with the Merger. Additionally, letter of credit term loans totaling $500 million (Term Loan C Facility) were repaid using $500 million of cash from collateral accounts used to backstop letters of credit. Fees and expenses related to the amendment to the Vistra Operations Credit Facilities totaled $42 million in the year ended December 31, 2018, of which $23 million was recorded as interest expense and other charges on the consolidated statements of operations, $9 million was capitalized as a reduction in the carrying amount of the debt and $10 million was capitalized as a noncurrent asset.

During the year ended December 31, 2020, we borrowed $1.075 billion and repaid $1.425 billion under the Revolving Credit Facility, with proceeds from the borrowings used for general corporate purposes.

The Vistra Operations Credit Facilities and related available capacity at December 31, 2020 are presented below.
December 31, 2020
Vistra Operations Credit FacilitiesMaturity DateFacility
Limit
Cash
Borrowings
Letters of Credit OutstandingAvailable
Capacity
Revolving Credit Facility (a)June 14, 2023$2,725 $— $737 $1,988 
Term Loan B-3 Facility (b)December 31, 20252,572 2,572 — 
Total Vistra Operations Credit Facilities$5,297 $2,572 $737 $1,988 
___________
(a)Revolving Credit Facility to be used for general corporate purposes. The Facility includes a $2.35 billion letter of credit sub-facility. Letters of credit outstanding reduce our available capacity. Cash borrowings under the Revolving Credit Facility are reported in short-term borrowings in our consolidated balance sheets.
(b)Beginning in 2020, cash borrowings under the Term Loan B-3 Facility are subject to a required scheduled quarterly payment in annual amount equal to 1.00% of the original principal amount with the balance paid at maturity. Amounts paid cannot be reborrowed.
In February 2018, June 2018 and November 2019, certain pricing terms for the Vistra Operations Credit Facilities were amended. We accounted for these transactions as modifications of debt. At December 31, 2020, cash borrowings under the Revolving Credit Facility would bear interest based on applicable LIBOR rates, plus a fixed spread of 1.75%, and there were no outstanding borrowings. Letters of credit issued under the Revolving Credit Facility bear interest of 1.75%. Amounts borrowed under the Term Loan B-3 Facility bears interest based on applicable LIBOR rates plus fixed spreads of 1.75%. At December 31, 2020, the weighted average interest rates before taking into consideration interest rate swaps on outstanding borrowings was 1.90% under the Term Loan B-3 Facility. The Vistra Operations Credit Facilities also provide for certain additional fees payable to the agents and lenders, including fronting fees with respect to outstanding letters of credit and availability fees payable with respect to any unused portion of the available Revolving Credit Facility.

Obligations under the Vistra Operations Credit Facilities are secured by a lien covering substantially all of Vistra Operations' (and its subsidiaries') consolidated assets, rights and properties, subject to certain exceptions set forth in the Vistra Operations Credit Facilities, provided that the amount of loans outstanding under the Vistra Operations Credit Facilities that may be secured by a lien covering certain principal properties of the Company is expressly limited by the terms of the Vistra Operations Credit Facilities.

The Vistra Operations Credit Facilities also permit certain hedging agreements to be secured on a pari-passu basis with the Vistra Operations Credit Facilities in the event those hedging agreements met certain criteria set forth in the Vistra Operations Credit Facilities.

The Vistra Operations Credit Facilities provide for affirmative and negative covenants applicable to Vistra Operations (and its restricted subsidiaries), including affirmative covenants requiring it to provide financial and other information to the agents under the Vistra Operations Credit Facilities and to not change its lines of business, and negative covenants restricting Vistra Operations' (and its restricted subsidiaries') ability to incur additional indebtedness, make investments, dispose of assets, pay dividends, grant liens or take certain other actions, in each case, except as permitted in the Vistra Operations Credit Facilities. Vistra Operations' ability to borrow under the Vistra Operations Credit Facilities is subject to the satisfaction of certain customary conditions precedent set forth therein.

The Vistra Operations Credit Facilities provide for certain customary events of default, including events of default resulting from non-payment of principal, interest or fees when due, material breaches of representations and warranties, material breaches of covenants in the Vistra Operations Credit Facilities or ancillary loan documents, cross-defaults under other agreements or instruments and the entry of material judgments against Vistra Operations. Solely with respect to the Revolving Credit Facility, and solely during a compliance period (which, in general, is applicable when the aggregate revolving borrowings and issued revolving letters of credit (in excess of $300 million) exceed 30% of the revolving commitments), the agreement includes a covenant that requires the consolidated first lien net leverage ratio, which is based on the ratio of net first lien debt compared to an EBITDA calculation defined under the terms of the Vistra Operations Credit Facilities, not to exceed 4.25 to 1.00. Although the period ended December 31, 2020 was not a compliance period, we would have been in compliance with this financial covenant if it was required to be tested at such time. Upon the existence of an event of default, the Vistra Operations Credit Facilities provide that all principal, interest and other amounts due thereunder will become immediately due and payable, either automatically or at the election of specified lenders.
Interest Rate Swaps — Vistra employs interest rate swaps to hedge our exposure to variable rate debt. As of December 31, 2020, Vistra has entered into the following series of interest rate swap transactions.
Notional AmountExpiration DateRate Range
Swapped to fixed$3,000July 20233.67 %-3.91%
Swapped to variable$700July 20233.20 %-3.23%
Swapped to fixed (a)$720February 20243.71 %-3.72%
Swapped to variable$720February 20243.20 %-3.20%
Swapped to fixed (b)$3,000July 20264.72 %-4.79%
Swapped to variable (b)$700July 20263.28 %-3.33%
____________
(a)In June 2018, we completed the novation of $1.959 billion of Vistra (legacy Dynegy) interest rate swaps to Vistra Operations, of which $398 million expired and $841 million were terminated in June 2019.
(b)Effective from July 2023 through July 2026.

During 2019, Vistra entered into $2.12 billion of new interest rate swaps, pursuant to which Vistra will pay a variable rate and receive a fixed rate. The terms of these new swaps were matched against the terms of certain existing swaps, effectively offsetting the hedge of the existing swaps and fixing the out-of-the-money position of such swaps. These matched swaps will settle over time, in accordance with the original contractual terms. The remaining existing swaps continue to hedge our exposure on $2.30 billion of debt through July 2026.

Secured Letter of Credit Facilities

In August and September 2020, Vistra entered into four uncommitted 364-day standby letter of credit facilities (Secured LOC Facilities) that are each secured by a first lien on all of Vista Operations' assets (which ranks pari passu with the Vistra Operations Credit Facilities). At December 31, 2020, $303 million of letters of credit were outstanding under the Secured LOC Facilities.

Alternate Letter of Credit Facilities

Two alternate letter of credit facilities (each, an Alternate LOC Facility) became effective in the year ended December 31, 2019. One Alternate LOC Facility with an aggregate facility limit of $250 million matured in December 2020. The remaining Alternate LOC Facility with an aggregate facility limit of $250 million matures in December 2021. At December 31, 2020, $245 million of letters of credit were outstanding under this Alternate LOC Facility.

Vistra Operations Senior Secured Notes

In 2019, Vistra Operations issued and sold $3.1 billion aggregate principal amount of senior secured notes (June 2019 Senior Secured Notes and the November 2019 Senior Secured Notes) in offerings (the June 2019 Senior Secured Notes Offering and the November 2019 Senior Secured Notes Offering) to eligible purchasers under Rule 144A and Regulation S under the Securities Act consisting of the following:
Senior Secured NotesMaturity YearInterest Terms
(Due Semiannually in Arrears)
June 2019
Senior Secured Notes Offering (a)
November 2019 Senior Secured Notes Offering (b)
3.550% Senior Secured Notes
2024January 15 and July 15$1,200 $300 
3.700% Senior Secured Notes
2027January 30 and July 30— 800 
4.300% Senior Secured Notes
2029January 15 and July 15800 — 
Total senior secured notes$2,000 $1,100 
Net proceeds$1,976 $1,099 
Debt issuance and other fees (c)$20 $10 
___________
(a)The June 2019 Senior Secured Notes were sold pursuant to a purchase agreement by and among Vistra Operations, certain direct and indirect subsidiaries of Vistra Operations and Citigroup Global Markets Inc., as representative of the several initial purchasers. Net proceeds, together with cash on hand, were used to prepay certain amounts outstanding and accrued interest (together with fees and expenses) under the Term Loan B Facility.
(b)The November 2019 Senior Secured Notes were sold pursuant to a purchase agreement by and among Vistra Operations, certain direct and indirect subsidiaries of Vistra Operations and J.P. Morgan Securities LLC., as representative of the several initial purchasers. Net proceeds, together with borrowings under the Term Loan B-3 Facility and cash on hand, were used to repay the entire amount outstanding and accrued interest (together with fees and expenses) under the Term Loan B-1 Facility.
(c)Capitalized as a reduction in the carrying amount of the debt.

The indenture (as may be amended or supplemented from time to time, the Vistra Operations Senior Secured Indenture) governing the June 2019 Senior Secured Notes and the November 2019 Senior Secured Notes (collectively, the Senior Secured Notes) provides for the full and unconditional guarantee by certain of Vistra Operations' current and future subsidiaries that also guarantee the Vistra Operations Credit Facilities. The Senior Secured Notes are secured by a first-priority security interest in the same collateral that is pledged for the benefit of the lenders under the Vistra Operations Credit Facilities, which consists of a substantial portion of the property, assets and rights owned by Vistra Operations and certain direct and indirect subsidiaries of Vistra Operations as subsidiary guarantors (collectively, the Guarantor Subsidiaries) as well as the stock of Vistra Operations held by Vistra Intermediate. The collateral securing the Senior Secured Notes will be released if Vistra Operations' senior, unsecured long-term debt securities obtain an investment grade rating from two out of the three rating agencies, subject to reversion if such rating agencies withdraw the investment grade rating of Vistra Operations' senior, unsecured long-term debt securities or downgrade such rating below investment grade. The Vistra Operations Senior Secured Indenture contains certain covenants and restrictions, including, among others, restrictions on the ability of Vistra Operations and its subsidiaries, as applicable, to create certain liens, merge or consolidate with another entity, and sell all or substantially all of their assets.

Vistra Operations Senior Unsecured Notes

In 2018 and 2019, Vistra Operations issued and sold $3.6 billion aggregate principal amount of senior unsecured notes in offerings (the August 2018 Senior Unsecured Notes Offering, the February 2019 Senior Unsecured Notes Offering and the June 2019 Senior Unsecured Notes Offerings) to eligible purchasers under Rule 144A and Regulation S under the Securities Act consisting of the following:
Senior Unsecured NotesMaturity YearInterest Terms
(Due Semiannually in Arrears)
August 2018 Senior Unsecured Notes Offering (a)February 2019 Senior Unsecured Notes Offering (b)June 2019
Senior Unsecured Notes Offering (c)
5.500% Senior Unsecured Notes
2026March 1 and September 1$1,000 $— $— 
5.625% Senior Unsecured Notes
2027February 15 and August 15— 1,300 — 
5.000% Senior Unsecured Notes
2027January 31 and July 31— — 1,300 
Total$1,000 $1,300 $1,300 
Net Proceeds$990 $1,287 $1,287 
Debt issuance and other fees (d)$12 $16 $13 
___________
(a)The 5.500% senior unsecured notes due 2026 (the August 2018 Senior Unsecured Notes) were sold pursuant to a purchase agreement by and among Vistra Operations, the Guarantor Subsidiaries and Citigroup Global Markets Inc., as representative of the several initial purchasers. Net proceeds, together with cash on hand and cash received from the funding of the Receivables Facility (see Note 10), were used to pay the purchase price and accrued interest (together with fees and expenses) required in connection with the 2018 Tender Offers (defined below).
(b)The 5.625% senior unsecured notes due 2027 (the February 2019 Senior Unsecured Notes) were sold pursuant to a purchase agreement by and among Vistra Operations, the Guarantor Subsidiaries and J.P. Morgan Securities LLC., as representative of the several initial purchasers. Net proceeds, together with cash on hand, were used to pay the purchase price and accrued interest (together with fees and expenses) required in connection with (i) the February 2019 Tender Offer, (defined below) and (ii) the redemption of approximately $35 million aggregate principal amount of our 7.375% senior unsecured notes due 2022 (7.375% senior notes) and approximately $25 million aggregate principal amount of our outstanding 8.034% senior unsecured notes due 2024 (8.034% senior notes).
(c)The 5.000% senior unsecured notes due 2027 (the June 2019 Senior Unsecured Notes) were sold pursuant to a purchase agreement by and among Vistra Operations, the Guarantor Subsidiaries and Goldman Sachs & Co. LLC, as representative of the several initial purchasers. Net proceeds, together with cash on hand, were used to pay the purchase price and accrued interest (together with fees and expenses) required in connection with (i) the June 2019 Tender Offer (defined below) and (ii) the redemption of approximately $306 million of our outstanding 7.375% senior notes and approximately $87 million of our 7.625% senior unsecured notes due 2024 (7.625% senior notes) in July 2019. We recorded an extinguishment gain of $2 million on the redemptions in the year ended December 31, 2019.
(d)Capitalized as a reduction in the carrying amount of the debt.

The indentures governing the June 2019 Senior Unsecured Notes, the February 2019 Senior Unsecured Notes and the August 2018 Senior Unsecured Notes (collectively, as each may be amended or supplemented from time to time, the Vistra Operations Senior Unsecured Indentures) provide for the full and unconditional guarantee by the Guarantor Subsidiaries of the punctual payment of the principal and interest on such notes. The Vistra Operations Senior Unsecured Indentures contain certain covenants and restrictions, including, among others, restrictions on the ability of Vistra Operations and its subsidiaries, as applicable, to create certain liens, merge or consolidate with another entity, and sell all or substantially all of their assets.

Debt Repurchase Program

In November 2018, our board of directors (the Board) authorized a bond repurchase program under which up to $200 million principal amount of outstanding Vistra Senior Unsecured Notes could be repurchased. Through June 30, 2019, $119 million principal amount of Vistra Senior Unsecured Notes had been repurchased. In July 2019, the Board authorized up to $1.0 billion to repay or repurchase any outstanding debt of the Company (or its subsidiaries), with that authority superseding the remaining availability under the $200 million bond repurchase program. Through April 2020, $684 million amount of debt had been repurchased under the $1.0 billion July 2019 authorization, including the repurchase of $100 million principal amount of Term Loan B-3 Facility borrowings discussed above and the redemption of $81 million aggregate principal amount outstanding of 8.000% senior unsecured notes due 2025 (8.000% senior notes) discussed below. In April 2020, the Board authorized up to $1.0 billion to repay or repurchase additional outstanding debt, with this new authority superseding and replacing the $316 million of availability under the previously authorized $1.0 billion debt repurchase program. Through December 31, 2020, approximately $666 million had been repurchased under the $1.0 billion April 2020 authorization, consisting of the redemption of the Vistra 5.875% senior unsecured notes due 2023 (5.875% senior notes) and the redemption of the Vistra 8.125% senior unsecured notes due 2026 (8.125% senior notes), each as described below.

Vistra Senior Unsecured Notes

On the Merger Date, Vistra assumed $6.138 billion principal amount of Dynegy's senior unsecured notes (Vistra Senior Unsecured Notes. In June 2018, each of the Company's subsidiaries that guaranteed the Vistra Operations Credit Facilities (and did not already guarantee the senior notes) provided a guarantee on the senior notes that remained outstanding.

Following the redemption, repurchase and tender offer transactions below, Vistra had no outstanding senior notes at the Parent level.
Vistra Senior Unsecured NotesMaturity Year2018 Redemptions/Repurchases (a)August
2018 Tender Offer (b)
February 2019 Tender Offer (c)June
2019 Tender Offer (d)
2019 Redemptions (e)2020 Redemptions (f)
6.750%Senior Unsecured Notes
2019$850 $— $— $— $— $— 
7.375% Senior Unsecured Notes
202243 — 1,193 173 341 — 
5.875% Senior Unsecured Notes
2023— — — — — 500 
7.625% Senior Unsecured Notes
202477 26 — 672 475 — 
8.034% Senior Unsecured Notes
2024— 163 — — 25 — 
8.000% Senior Unsecured Notes
2025— 669 — — — 81 
8.125%Senior Unsecured Notes
2026— 684 — — — 166 
Total$970 $1,542 $1,193 $845 $841 $747 
Extinguishment gain/(loss)$— $(27)$$$11 $11 
____________
(a)In May 2018, $850 million of outstanding 6.75% senior unsecured notes due 2019 were redeemed at a redemption price of 101.688% of the aggregate principal amount, plus accrued and unpaid interest up to but not including the date of redemption. Fees and expenses related to the redemption totaled $14 million in the year ended December 31, 2018 and were recorded as interest expense and other charges on the consolidated statements of operations. In addition, Vistra repurchased $119 million of Vistra Senior Unsecured Notes under the bond repurchase program described above.
(b)In August 2018, Vistra used the net proceeds from the August 2018 Senior Unsecured Notes Offering, proceeds from the Receivables Facility (see Note 10) and cash on hand to fund cash tender offers (the 2018 Tender Offers) to purchase for cash $1.542 billion aggregate principal amount of Vistra Senior Unsecured Notes.
(c)In February 2019, Vistra used the net proceeds from the February 2019 Senior Unsecured Notes Offering to fund a cash tender offer (the February 2019 Tender Offer) to purchase for cash $1.193 billion aggregate principal amount of 7.375% senior notes.
(d)In June 2019, Vistra used the net proceeds from the June 2019 Notes Offering to fund a cash tender offer (the June 2019 Tender Offer) to purchase for cash $173 million of 7.375% senior notes and $672 million of 7.625% senior notes. In July 2019, Vistra accepted and settled an additional approximately $1 million aggregate principal amount of outstanding 7.625% senior notes that were tendered after the early tender date of the June 2019 Tender Offer.
(e)In November 2019, Vistra redeemed $387 million aggregate principal amount outstanding of 7.625% senior notes at a redemption price equal to 103.8% of the aggregate principal amount thereof, plus accrued and unpaid interest to, but excluding, the date of redemption (the 2019 Redemption). Vistra redeemed $341 million, $87 million and $25 million aggregate principal amount of 7.375% senior notes, 7.625% senior notes and 8.034% senior notes, respectively, using proceeds from the February 2019 Senior Unsecured Notes Offering and the June 2019 Senior Unsecured Notes Offerings discussed above.
(f)In January 2020, June 2020 and July 2020, Vistra redeemed aggregate principal amounts of $81 million of 8.000% senior notes, $500 million of 5.875% senior notes and $166 million of 8.125% senior notes, respectively, at redemption prices of 104%, 100.979% and 104.063%, respectively, of the aggregate principal amounts thereof, plus accrued and unpaid interest to, but excluding, the dates of redemption (the 2020 Redemptions, and together with the 2019 Redemption, the Redemptions).

February 2019 Consent Solicitation — In connection with the February 2019 Tender Offer, Vistra also commenced solicitation of consents from holders of the 7.375% senior notes. Vistra received the requisite consents from the holders of the 7.375% senior notes and amended the indenture governing these senior notes to, among other things, eliminate substantially all of the restrictive covenants and certain events of default.

August 2018 Consent Solicitations — In connection with the 2018 Tender Offers, Vistra also commenced solicitations of consents from holders of the 7.375% senior notes, the 7.625% senior notes, the 8.034% senior notes, the 8.000% senior notes and the 8.125% senior notes to amend certain provisions of the applicable indentures governing each series of senior notes and the registration rights agreement with respect to the 8.125% senior notes. Vistra received the requisite consents from the holders of the 8.034% senior notes, the 8.000% senior notes and the 8.125% senior notes (collectively, the Consent Senior Notes) and amended (a) the indentures governing each series of the applicable senior notes to, among other things, eliminate substantially all of the restrictive covenants and certain events of default and (b) the registration rights agreement with respect to the 8.125% senior notes to remove, among other things, the requirement that Vistra commence an exchange offer to issue registered securities in exchange for the existing, nonregistered notes.

Other Long-Term Debt

Amortizing Notes — On the Merger Date, Vistra assumed the obligations of Dynegy's senior unsecured amortizing note (Amortizing Notes) that matured on July 1, 2019. The Amortizing Notes were issued in connection with the issuance of the tangible equity units (TEUs) by Dynegy (see Note 14). Each installment payment per Amortizing Note was paid in cash and constituted a partial repayment of principal and a payment of interest, computed at an annual rate of 7.00%. Interest was calculated on the basis of a 360-day year consisting of twelve 30-day months. Payments were applied first to the interest due and payable and then to the reduction of the unpaid principal amount, allocated as set forth in the indenture (Amortizing Notes Indenture). On the maturity date, the Company paid all amounts due under the Amortizing Notes Indenture and the Amortizing Notes Indenture ceased to be of further force and effect.

Forward Capacity Agreements — On the Merger Date, the Company assumed the obligation of Dynegy's agreements under which a portion of the PJM capacity that cleared for Planning Years 2018-2019, 2019-2020 and 2020-2021 was sold to a financial institution (Forward Capacity Agreements). The buyer in this transaction will receive capacity payments from PJM during the Planning Years 2020-2021 in the amount of $45 million. We will continue to be subject to the performance obligations as well as any associated performance penalties and bonus payments for those planning years. As a result, this transaction is accounted for as long-term debt with an implied interest rate of 1.14%.

Equipment Financing Agreements — On the Merger Date, the Company assumed Dynegy's Equipment Financing Agreements. Under certain of our contractual service agreements in which we receive maintenance and capital improvements for our gas-fueled generation fleet, we have obtained parts and equipment intended to increase the output, efficiency and availability of our generation units. We financed these parts and equipment under agreements with maturities ranging from 2021 to 2026.

Mandatorily Redeemable Subsidiary Preferred Stock — In October 2019, PrefCo voluntarily redeemed the entire $70 million aggregate principal amount outstanding of its authorized preferred stock at a price per share equal to the preferred liquidation amount, plus accrued and unpaid dividends to and including the date of redemption.
Debt Assumed in Crius Transaction — On the Crius Acquisition Date, Vistra assumed $140 million in long-term debt obligations in connection with the Crius Transaction consisting of the following:

$44 million of 9.5% promissory notes due July 2025 (2025 promissory notes);
$8 million of 2% Connecticut Department of Economic and Community Development (CT DECD) term loans due February 2027; and
$88 million of borrowings and $9 million of issued letters of credit under the legacy Crius credit facility.

In July 2019, borrowings of $88 million under the legacy Crius credit facility were repaid using cash on hand. In November 2019, (i) borrowings of approximately $38 million under the 2025 promissory notes were repaid using cash on hand and (ii) borrowings of approximately $2 million were offset by legacy indemnification obligations of the holders of the 2025 promissory notes. In November 2019, borrowings of $8 million under the Connecticut Department of Economic and Community Development term loans were repaid using cash on hand.

Vistra (legacy Dynegy) Credit Agreement — On the Merger Date, Vistra assumed the obligations under Dynegy's $3.563 billion credit agreement consisting of a $2.018 billion senior secured term loan facility due 2024 and a $1.545 billion senior secured revolving credit facility. As of the Merger Date, there were no cash borrowings and $656 million of letters of credit outstanding under the senior secured revolving credit facility. On April 23, 2018, $70 million of the senior secured revolving credit facility matured. In June 2018, the $2.018 billion senior secured term loan facility due 2024 was repaid using proceeds from the Term Loan B-3 Facility. In addition, all letters of credit outstanding under the senior secured revolving credit facility were replaced with letters of credit under the amended Vistra Operations Credit Facilities discussed above, and the revolving credit facility assumed from Dynegy in connection with the Merger was paid off in full and terminated.

Maturities

Long-term debt maturities at December 31, 2020 are as follows:
December 31, 2020
2021$98 
202244 
202340 
20241,540 
20252,470 
Thereafter5,206 
Unamortized premiums, discounts and debt issuance costs(68)
Total long-term debt, including amounts due currently$9,330 
v3.20.4
Leases
12 Months Ended
Dec. 31, 2020
Leases [Abstract]  
Leases LEASES
Vistra has both finance and operating leases for real estate, rail cars and equipment. Our leases have remaining lease terms for 1 to 37 years. Our leases include options to renew up to 15 years. Certain leases also contain options to terminate the lease.

Lease Cost

The following table presents costs related to lease activities:
Year Ended December 31,
20202019
Operating lease cost$14 $14 
Finance lease:
Finance lease right-of-use asset amortization
Interest on lease liabilities
Total finance lease cost14 
Variable lease cost (a)29 26 
Short-term lease cost31 19 
Sublease income (b)(8)(8)
Net lease cost$80 $59 
____________
(a)Represents coal stockpile management services, common area maintenance services and rail car payments based on the number of rail cars used.
(b)Represents sublease income related to real estate leases.

Balance Sheet Information

The following table presents lease related balance sheet information:
December 31,
20202019
Lease assets:
Operating lease right-of-use assets$45 $44 
Finance lease right-of-use assets (net of accumulated depreciation)182 $59 
Total lease right-of-use assets227 103 
Current lease liabilities:
Operating lease liabilities14 
Finance lease liabilities
Total current lease liabilities16 22 
Noncurrent lease liabilities:
Operating lease liabilities40 41 
Finance lease liabilities206 78 
Total noncurrent lease liabilities246 119 
Total lease liabilities$262 $141 
Cash Flows and Other Information

The following table presents lease related cash flows and other information:
Year Ended December 31,
20202019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases$17 $17 
Operating cash flows from finance leases
Finance cash flows from finance leases10 
Non-cash disclosure upon commencement of new lease:
Right-of-use assets obtained in exchange for new operating lease liabilities14 95 
Right-of-use assets obtained in exchange for new finance lease liabilities108 13 
Non-cash disclosure upon modification of existing lease:
Modification of operating lease right-of-use assets(1)(41)
Modification of finance lease right-of-use assets23 50 

Weighted Average Remaining Lease Term

The following table presents weighted average remaining lease term information:
December 31,
20202019
Weighted average remaining lease term:
Operating lease12.3 years7.5 years
Finance lease24.2 years16.2 years
Weighted average discount rate:
Operating lease5.80%5.34 %
Finance lease4.92%5.84 %

Maturity of Lease Liabilities

The following table presents maturity of lease liabilities:
Operating LeaseFinance LeaseTotal Lease
2021$11 $14 $25 
202220 28 
202319 28 
202419 24 
202519 22 
Thereafter41 385 426 
Total lease payments77 476 553 
Less: Interest(29)(262)(291)
Present value of lease liabilities$48 $214 $262 

As of December 31, 2020, we have approximately $7 million of operating leases that have not yet commenced.
Leases LEASES
Vistra has both finance and operating leases for real estate, rail cars and equipment. Our leases have remaining lease terms for 1 to 37 years. Our leases include options to renew up to 15 years. Certain leases also contain options to terminate the lease.

Lease Cost

The following table presents costs related to lease activities:
Year Ended December 31,
20202019
Operating lease cost$14 $14 
Finance lease:
Finance lease right-of-use asset amortization
Interest on lease liabilities
Total finance lease cost14 
Variable lease cost (a)29 26 
Short-term lease cost31 19 
Sublease income (b)(8)(8)
Net lease cost$80 $59 
____________
(a)Represents coal stockpile management services, common area maintenance services and rail car payments based on the number of rail cars used.
(b)Represents sublease income related to real estate leases.

Balance Sheet Information

The following table presents lease related balance sheet information:
December 31,
20202019
Lease assets:
Operating lease right-of-use assets$45 $44 
Finance lease right-of-use assets (net of accumulated depreciation)182 $59 
Total lease right-of-use assets227 103 
Current lease liabilities:
Operating lease liabilities14 
Finance lease liabilities
Total current lease liabilities16 22 
Noncurrent lease liabilities:
Operating lease liabilities40 41 
Finance lease liabilities206 78 
Total noncurrent lease liabilities246 119 
Total lease liabilities$262 $141 
Cash Flows and Other Information

The following table presents lease related cash flows and other information:
Year Ended December 31,
20202019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases$17 $17 
Operating cash flows from finance leases
Finance cash flows from finance leases10 
Non-cash disclosure upon commencement of new lease:
Right-of-use assets obtained in exchange for new operating lease liabilities14 95 
Right-of-use assets obtained in exchange for new finance lease liabilities108 13 
Non-cash disclosure upon modification of existing lease:
Modification of operating lease right-of-use assets(1)(41)
Modification of finance lease right-of-use assets23 50 

Weighted Average Remaining Lease Term

The following table presents weighted average remaining lease term information:
December 31,
20202019
Weighted average remaining lease term:
Operating lease12.3 years7.5 years
Finance lease24.2 years16.2 years
Weighted average discount rate:
Operating lease5.80%5.34 %
Finance lease4.92%5.84 %

Maturity of Lease Liabilities

The following table presents maturity of lease liabilities:
Operating LeaseFinance LeaseTotal Lease
2021$11 $14 $25 
202220 28 
202319 28 
202419 24 
202519 22 
Thereafter41 385 426 
Total lease payments77 476 553 
Less: Interest(29)(262)(291)
Present value of lease liabilities$48 $214 $262 

As of December 31, 2020, we have approximately $7 million of operating leases that have not yet commenced.
v3.20.4
Commitments and Contingencies
12 Months Ended
Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]  
Commitments And Contingencies COMMITMENTS AND CONTINGENCIES
Contractual Commitments

At December 31, 2020, we had contractual commitments under long-term service and maintenance contracts, energy-related contracts, leases and other agreements as follows.
Long-Term Service and Maintenance ContractsCoal purchase and
transportation agreements
Pipeline transportation and storage reservation feesNuclear
Fuel Contracts
Other
Contracts
2021$165 $516 $100 $92 $256 
2022186 47 73 43 49 
2023137 34 49 57 29 
2024142 36 36 40 24 
2025170 37 30 36 11 
Thereafter1,824 79 111 107 80 
Total$2,624 $749 $399 $375 $449 

The table above excludes TRA and pension and OPEB plan obligations due to the uncertainty in the timing of those payments.

Expenditures under our coal purchase and coal transportation agreements totaled $845 million, $1.092 billion, and $955 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Rent reported as operating costs and SG&A expenses totaled $111 million, $89 million, and $74 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Guarantees

We have entered into contracts that contain guarantees to unaffiliated parties that could require performance or payment under certain conditions. As of December 31, 2020, there are no material outstanding claims related to our guarantee obligations, and we do not anticipate we will be required to make any material payments under these guarantees in the near term.

Letters of Credit

At December 31, 2020, we had outstanding letters of credit totaling $1.286 billion as follows:

$878 million to support commodity risk management collateral requirements in the normal course of business, including over-the-counter and exchange-traded transactions and collateral postings with ISOs/RTOs;
$190 million to support battery and solar development projects;
$34 million to support executory contracts and insurance agreements;
$102 million to support our REP financial requirements with the PUCT; and
$82 million for other credit support requirements.

Surety Bonds

At December 31, 2020, we had outstanding surety bonds totaling $100 million to support performance under various contracts and legal obligations in the normal course of business.
Litigation and Regulatory Proceedings

Our material legal proceedings and regulatory proceedings affecting our business are described below. We believe that we have valid defenses to the legal proceedings described below and intend to defend them vigorously. We also intend to participate in the regulatory processes described below. We record reserves for estimated losses related to these matters when information available indicates that a loss is probable and the amount of the loss, or range of loss, can be reasonably estimated. As applicable, we have established an adequate reserve for the matters discussed below. In addition, legal costs are expensed as incurred. Management has assessed each of the following legal matters based on current information and made a judgment concerning its potential outcome, considering the nature of the claim, the amount and nature of damages sought, and the probability of success. Unless specified below, we are unable to predict the outcome of these matters or reasonably estimate the scope or amount of any associated costs and potential liabilities, but they could have a material impact on our results of operations, liquidity, or financial condition. As additional information becomes available, we adjust our assessment and estimates of such contingencies accordingly. Because litigation and rulemaking proceedings are subject to inherent uncertainties and unfavorable rulings or developments, it is possible that the ultimate resolution of these matters could be at amounts that are different from our currently recorded reserves and that such differences could be material.

Gas Index Pricing Litigation — We, through our subsidiaries, and other companies are named as defendants in several lawsuits claiming damages resulting from alleged price manipulation through false reporting of natural gas prices to various index publications, wash trading and churn trading from 2000-2002. The plaintiffs in these cases allege that the defendants engaged in an antitrust conspiracy to inflate natural gas prices during the relevant time period and seek damages under the respective state antitrust statutes. We remain as defendants in two consolidated putative class actions (Wisconsin) and one individual action (Kansas) both pending in federal court in those states. The Kansas action is currently on appeal in the U.S. Court of Appeals for the Tenth Circuit.

Wood River Rail Dispute — In November 2017, Dynegy Midwest Generation, LLC (DMG) received notification that BNSF Railway Company and Norfolk Southern Railway Company were initiating dispute resolution related to DMG's suspension of its Wood River Rail Transportation Agreement with the railroads. Settlement discussions required under the dispute resolution process have been unsuccessful. In March 2018, BNSF Railway Company (BNSF) and Norfolk Southern Railway Company (NS) filed a demand for arbitration and an arbitration hearing is currently scheduled for March 2021.

Coffeen and Duck Creek Rail Disputes — In April 2020, IPH, LLC (IPH) received notification that BNSF and NS were initiating dispute resolution related to IPH's suspension of its Coffeen Rail Transportation Agreement with the railroads, and Illinois Power Resources Generating, LLC (IPRG), received notification that BNSF was initiating dispute resolution related to IPRG's suspension of its Duck Creek Rail Transportation Agreement with BNSF. In November 2019, IPH and IPRG sent suspension notices to the railroads asserting that the MPS rule requirement to retire at least 2,000 megawatts of generation (see discussion below) was a change-in-law under the agreement that rendered continued operation of the plants no longer economically feasible. In addition, IPH and IPRG asserted that the MPS rule's retirement requirement also qualified as a force majeure event under the agreements excusing performance.

ME2C Patent Dispute — In July 2019, Midwest Energy Emissions Corporation and MES Inc. (collectively, the plaintiffs) filed a patent infringement complaint in federal court in Delaware against numerous parties, including Vistra and some of its subsidiaries (collectively, the Vistra defendants), and its amended complaint in July 2020. The amended complaint alleges that the Vistra defendants infringed five patents owned by the plaintiffs by using specific processes for mercury control at certain coal-fueled plants. The amended complaint seeks injunctive relief and unspecified damages. In July 2020, the plaintiffs and the Vistra defendants entered into an agreement resolving all the claims alleged against the Vistra defendants in the complaint. The court signed its stipulation and order of dismissal in July 2020, dismissing the Vistra defendants from the lawsuit.
Climate Change

In January 2021, the Biden administration issued a series of Executive Orders, including one titled Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis (the Environment Executive Order) which directed agencies, including the EPA, to review various agency actions promulgated during the prior administration and take action where the previous administration's action conflicts with national objectives. Several of the EPA agency actions discussed below are now subject to this review.

Greenhouse Gas Emissions

In August 2015, the EPA finalized rules to address greenhouse gas (GHG) emissions from electricity generation units, referred to as the Clean Power Plan, including rules for existing facilities that would establish state-specific emissions rate goals to reduce nationwide CO2 emissions. Various parties filed petitions for review in the U.S. Court of Appeals for the District of Columbia Circuit (D.C. Circuit Court). In July 2019, petitioners filed a joint motion to dismiss in light of the EPA's new rule that replaces the Clean Power Plan, the Affordable Clean Energy rule, discussed below. In September 2019, the D.C. Circuit Court granted petitioners' motion to dismiss and dismissed all of the petitions challenging the Clean Power Plan as moot.

In July 2019, the EPA finalized a rule to repeal the Clean Power Plan, with new regulations addressing GHG emissions from existing coal-fueled electric generation units, referred to as the Affordable Clean Energy (ACE) rule. The ACE rule develops emission guidelines that states must use when developing plans to regulate GHG emissions from existing coal-fueled electric generating units. The ACE rule set a deadline of July 2022 for states to submit their plans for regulating GHG emissions from existing facilities. States where we operate coal plants (Texas, Illinois and Ohio) have begun the development of their state plans to comply with the rule. Environmental groups and certain states filed petitions for review of the ACE rule and the repeal of the Clean Power Plan in the D.C. Circuit Court, and the D.C. Circuit Court heard argument on those issues in October 2020. In January 2021, the D.C. Circuit Court vacated the ACE rule and remanded the rule to the EPA for further action. In its decision, the D.C. Circuit Court concluded that the EPA's basis for repealing the Clean Power Plan and adopting the ACE rule was not supported by the Clean Air Act. Additionally, in December 2018, the EPA issued proposed revisions to the emission standards for new, modified and reconstructed units. Vistra submitted comments on that proposed rulemaking in March 2019. In January 2021, the EPA, just prior to the transition to the Biden administration, issued a final rule setting forth a significant contribution finding for the purpose of regulating GHG emissions from new, modified, or reconstructed electric utility generating units. The final rule excludes sectors from future regulation where GHG emissions make up less than three percent of U.S. GHG emissions. The final rule did not set any specific emission limits for new, modified, or reconstructed electric utility generating units. The ACE rule and the rule on significant contribution are subject to the Environment Executive Order discussed above.

Regional Haze — Reasonable Progress and Best Available Retrofit Technology (BART) for Texas

In October 2017, the EPA issued a final rule addressing BART for Texas electricity generation units, with the rule serving as a partial approval of Texas' 2009 State Implementation Plan (SIP) and a partial Federal Implementation Plan (FIP). For SO2, the rule established an intrastate Texas emission allowance trading program as a "BART alternative" that operates in a similar fashion to a CSAPR trading program. The program includes 39 generating units (including our Martin Lake, Big Brown, Monticello, Sandow 4, Coleto Creek, Stryker 2 and Graham 2 plants). The compliance obligations in the program started on January 1, 2019. The retirements of our Monticello, Big Brown and Sandow 4 plants have enhanced our ability to comply with this BART rule for SO2. For NOX, the rule adopted the CSAPR's ozone program as BART and for particulate matter, the rule approved Texas's SIP that determines that no electricity generation units are subject to BART for particulate matter. Various parties filed a petition challenging the rule in the U.S. Court of Appeals for the Fifth Circuit (Fifth Circuit Court) as well as a petition for reconsideration filed with the EPA. Luminant intervened on behalf of the EPA in the Fifth Circuit Court action. In March 2018, the Fifth Circuit Court abated its proceedings pending conclusion of the EPA's reconsideration process. In August 2020, the EPA issued a final rule affirming the prior BART final rule but also included additional revisions that were proposed in November 2019. In October 2020, environmental groups petitioned for review of this rule in both the D.C. Circuit Court and the Fifth Circuit Court. Briefing is underway on the proper venue for any challenge to the final rule. As finalized, we expect that we will be able to comply with the rule. The BART rule is subject to the Environment Executive Order discussed above.
Affirmative Defenses During Malfunctions

In May 2015, the EPA finalized a rule requiring 36 states, including Texas, Illinois and Ohio, to remove or replace either EPA-approved exemptions or affirmative defense provisions for excess emissions during upset events and unplanned maintenance and startup and shutdown events, referred to as the SIP Call. Various parties (including Luminant, the State of Texas and the State of Ohio) filed petitions for review of the EPA's final rule, and all of those petitions were consolidated in the D.C. Circuit Court. In April 2017, the D.C. Circuit Court ordered the case to be held in abeyance. In April 2019, the EPA Region 6 proposed a rule to withdraw the SIP Call with respect to the Texas affirmative defense provisions. We submitted comments on that proposed rulemaking in June 2019. In February 2020, the EPA issued the final rule withdrawing the Texas SIP Call. In April 2020, a group of environmental petitioners, including the Sierra Club, filed a petition in the D.C. Circuit Court challenging the EPA's action with respect to Texas. Briefing is currently underway in the challenge to the EPA's action with respect to Texas. In October 2020, the EPA issued new guidance on the inclusion of startup, shutdown and malfunction (SSM) provisions in SIPs, which is intended to supersede the policy in the multi-state SIP Call. The guidance provides that the SIPs may contain provisions for SSM events if certain conditions are met. The EPA SSM guidance is subject to the Environment Executive Order discussed above.

Illinois Multi-Pollutant Standards (MPS)

In August 2019, changes proposed by the Illinois Pollution Control Board to the MPS rule, which places NOX, SO2 and mercury emissions limits on our coal plants located in MISO went into effect. Under the revised MPS rule, our allowable SO2 and NOX emissions from the MISO fleet are 48% and 42% lower, respectively, than prior to the rule changes. The revised MPS rule requires the continuous operation of existing selective catalytic reduction (SCR) control systems during the ozone season, requires SCR-controlled units to meet an ozone season NOX emission rate limit, and set an additional, site-specific annual SO2 limit for our Joppa Power Station. Additionally, in 2019, the Company retired its Havana, Hennepin, Coffeen and Duck Creek plants in order to comply with the MPS rule's requirement to retire at least 2,000 MW of our generation in MISO. See Note 4 for information regarding the retirement of these four plants.

SO2 Designations for Texas

In November 2016, the EPA finalized its nonattainment designations for counties surrounding our Big Brown, Monticello and Martin Lake generation plants. The final designations require Texas to develop nonattainment plans for these areas. In February 2017, the State of Texas and Luminant filed challenges to the nonattainment designations in the Fifth Circuit Court. Subsequently, in October 2017, the Fifth Circuit Court granted the EPA's motion to hold the case in abeyance considering the EPA's representation that it intended to revisit the nonattainment rule. In December 2017, the TCEQ submitted a petition for reconsideration to the EPA. In August 2019, the EPA issued a proposed Error Correction Rule for all three areas, which, if finalized, would revise its previous nonattainment designations and each area at issue would be designated unclassifiable. In September 2019, we submitted comments in support of the proposed Error Correction Rule. In April 2020, the Sierra Club filed suit to compel the EPA to issue a Finding of Failure to submit an attainment plan with respect to the three areas in Texas. In August 2020, the EPA issued a Finding of Failure for Texas to submit an attainment plan. In September 2020, the EPA proposed a "Clean Data" determination for the areas surrounding the retired Big Brown and Monticello plants, which, if finalized, would redesignate those areas as attainment based on monitoring data supporting an attainment designation. We expect the TCEQ to develop a SIP for Texas for submittal to the EPA in 2021.
Effluent Limitation Guidelines (ELGs)

In November 2015, the EPA revised the ELGs for steam electricity generation facilities, which will impose more stringent standards (as individual permits are renewed) for wastewater streams, such as flue gas desulfurization (FGD), fly ash, bottom ash and flue gas mercury control wastewaters. Various parties filed petitions for review of the ELG rule, and the petitions were consolidated in the Fifth Circuit Court. In April 2017, the EPA granted petitions requesting reconsideration of the ELG rule and administratively stayed the rule's compliance date deadlines. In August 2017, the EPA announced that its reconsideration of the ELG rule would be limited to a review of the effluent limitations applicable to FGD and bottom ash wastewaters and the agency subsequently postponed the earliest compliance dates in the ELG rule for the application of effluent limitations for FGD and bottom ash wastewaters from November 1, 2018 to November 1, 2020. Based on these administrative developments, the Fifth Circuit Court agreed to sever and hold in abeyance challenges to effluent limitations. The remainder of the case proceeded, and in April 2019 the Fifth Circuit Court vacated and remanded portions of the EPA's ELG rule pertaining to effluent limitations for legacy wastewater and leachate. In November 2019, the EPA issued a proposal that would extend the compliance deadline for FGD wastewater to no later than December 31, 2025 and maintains the December 31, 2023 compliance date for bottom ash transport water. The proposal also creates new sub-categories of facilities with more flexible FGD compliance options, including a retirement exemption to 2028 and a low utilization boiler exemption. The proposed rule also modified some of the FGD final effluent limitations. We filed comments on the proposal in January 2020. The EPA published the final rule in October 2020. The final rule extends the compliance date for both FGD and bottom ash transport water to no later than December 2025, as negotiated with the state permitting agency. Additionally, the final rule allows for a retirement exemption that exempts facilities certifying that units will retire by December 2028 provided certain effluent limitations are met. Notification to the state agency on the retirement exemption is due by October 2021. In November 2020, environmental groups petitioned for review of the new ELG revisions, and Vistra subsidiaries filed a motion to intervene in support of the EPA in December 2020. The final rule is subject to the Environment Executive Order discussed above.

Coal Combustion Residuals (CCR)/Groundwater

In July 2018, the EPA published a final rule, which became effective in August 2018, that amends certain provisions of the CCR rule that the agency issued in 2015. Among other changes, the 2018 revisions extended closure deadlines to October 31, 2020, related to the aquifer location restriction and groundwater monitoring requirements. Also, in August 2018, the D.C. Circuit Court issued a decision that vacates and remands certain provisions of the 2015 CCR rule, including an applicability exemption for legacy impoundments. In December 2019, the EPA issued a proposed rule containing a revised closure deadline for unlined CCR impoundments and new procedures for seeking extensions of that revised closure deadline. We filed comments on the proposal in January 2020. In August 2020, the EPA issued a rule finalizing the December 2019 proposal, establishing a deadline of April 11, 2021 to cease receipt of waste and initiate closure at unlined CCR impoundments. The final rule allows a generation plant to seek the EPA's approval to extend this deadline if no alternative disposal capacity is available and either a conversion to comply with the CCR rule is underway or retirement will occur by either 2023 or 2028 (depending on the size of the impoundment at issue). Prior to the November 2020 deadline, we submitted applications to the EPA requesting compliance extensions under both conversion and retirement scenarios. In November 2020, environmental groups petitioned for review of this rule in the D.C. Circuit Court, and Vistra subsidiaries filed a motion to intervene in support of the EPA in December 2020. Also, in November 2020, the EPA finalized a rule that would allow an alternative liner demonstration for certain qualifying facilities. In November 2020, we submitted an alternate liner demonstration for one CCR unit at Martin Lake. In October 2020, the EPA published an advanced notice of proposed rulemaking requesting information to inform the EPA in the development of a rule to address legacy impoundments that existed prior to the 2015 CCR regulation as required by the August 2018 D.C. Circuit Court decision. We filed comments on this proposal in February 2021. The rules on revised closure deadlines and alternative liner demonstrations are subject to the Environment Executive Order discussed above.

MISO — In 2012, the Illinois Environmental Protection Agency (IEPA) issued violation notices alleging violations of groundwater standards onsite at our Baldwin and Vermilion facilities' CCR surface impoundments. These violation notices remain unresolved; however, in 2016, the IEPA approved our closure and post-closure care plans for the Baldwin old east, east, and west fly ash CCR surface impoundments. We are working towards implementation of those closure plans.
At our retired Vermilion facility, which was not subject to the EPA's 2015 CCR rule until the aforementioned D.C. Circuit Court decision in August 2018, we submitted proposed corrective action plans involving closure of two CCR surface impoundments (i.e., the old east and the north impoundments) to the IEPA in 2012, and we submitted revised plans in 2014. In May 2017, in response to a request from the IEPA for additional information regarding the closure of these Vermilion surface impoundments, we agreed to perform additional groundwater sampling and closure options and riverbank stabilizing options. In May 2018, Prairie Rivers Network filed a citizen suit in federal court in Illinois against DMG, alleging violations of the Clean Water Act for alleged unauthorized discharges. In August 2018, we filed a motion to dismiss the lawsuit. In November 2018, the district court granted our motion to dismiss and judgment was entered in our favor. Plaintiffs have appealed the judgment to the U.S. Court of Appeals for the Seventh Circuit and argument was heard in November 2020. In April 2019, PRN also filed a complaint against DMG before the IPCB, alleging that groundwater flows allegedly associated with the ash impoundments at the Vermilion site have resulted in exceedances both of surface water standards and Illinois groundwater standards dating back to 1992. This matter is in the very early stages.

In 2012, the IEPA issued violation notices alleging violations of groundwater standards at the Newton and Coffeen facilities' CCR surface impoundments. We are addressing these CCR surface impoundments in accordance with the federal CCR rule. In June 2018, the IEPA issued a violation notice for alleged seep discharges claimed to be coming from the surface impoundments at our retired Vermilion facility and that notice has since been referred to the Illinois Attorney General.

In December 2018, the Sierra Club filed a complaint with the IPCB alleging the disposal and storage of coal ash at the Coffeen, Edwards and Joppa generation facilities are causing exceedances of the applicable groundwater standards.

In July 2019, coal ash disposal and storage legislation in Illinois was enacted. The legislation addresses state requirements for the proper closure of coal ash ponds in the state of Illinois. The law tasks the IEPA and the IPCB to set up a series of guidelines, rules and permit requirements for closure of ash ponds. In March 2020, the IEPA issued its proposed rule, and we expect the rulemaking process should be completed by early 2021. Under the proposed rule, coal ash impoundment owners would be required to submit a closure alternative analysis to the IEPA for the selection of the best method for coal ash remediation at a particular site. The proposed rule does not mandate closure by removal at any site. Public hearings for the proposed rule were held in August 2020 and September 2020. We expect that the rule will be finalized by March 2021.

For all of the above matters, if certain corrective action measures, including groundwater treatment or removal of ash, are required at any of our coal-fueled facilities, we may incur significant costs that could have a material adverse effect on our financial condition, results of operations, and cash flows. Until the revisions to the Illinois coal ash rulemaking are finalized and we undertake further site specific evaluations required by each program we will not know the full range of costs of groundwater remediation, if any, that ultimately may be required under those rules. However, the currently anticipated CCR surface impoundment and landfill closure costs, as contained in our AROs, reflect the costs of closure methods that our operations and environmental services teams believe are appropriate and protective of the environment for each location.

MISO 2015-2016 Planning Resource Auction

In May 2015, three complaints were filed at FERC regarding the Zone 4 results for the 2015-2016 planning resource auction (PRA) conducted by MISO. Dynegy is a named party in one of the complaints. The complainants, Public Citizen, Inc., the Illinois Attorney General and Southwestern Electric Cooperative, Inc. (Complainants), challenged the results of the PRA as unjust and unreasonable, requested rate relief/refunds, and requested changes to the MISO planning resource auction structure going forward. Complainants also alleged that Dynegy may have engaged in economic or physical withholding in Zone 4 constituting market manipulation in the PRA. The Independent Market Monitor for MISO (MISO IMM), which was responsible for monitoring the PRA, determined that all offers were competitive and that no physical or economic withholding occurred. The MISO IMM also stated, in a filing responding to the complaints, that there is no basis for the remedies sought by the Complainants. We filed our answer to these complaints explaining that we complied fully with the terms of the MISO tariff in connection with the PRA and disputing the allegations. The Illinois Industrial Energy Consumers filed a related complaint at FERC against MISO in June 2015 requesting prospective changes to the MISO tariff. Dynegy also responded to this complaint with respect to Dynegy's conduct alleged in the complaint.

In October 2015, FERC issued an order of nonpublic, formal investigation (the investigation) into whether market manipulation or other potential violations of FERC orders, rules and regulations occurred before or during the PRA.
In December 2015, FERC issued an order on the complaints requiring a number of prospective changes to the MISO tariff provisions effective as of the 2016-2017 planning resource auction. The order did not address the arguments of the Complainants regarding the PRA and stated that those issues remained under consideration and would be addressed in a future order.

In July 2019, FERC issued an order denying the remaining issues raised by the complaints and noted that the investigation into Dynegy was closed. FERC found that Dynegy's conduct did not constitute market manipulation and the results of the PRA were just and reasonable because the PRA was conducted in accordance with MISO's tariff. With the issuance of the order, this matter has been resolved in Dynegy's favor. The request for rehearing was denied by FERC in March 2020. The order was appealed by Public Citizen, Inc. to the D.C. Circuit Court in May 2020, and Vistra, Dynegy and Illinois Power Marketing Company intervened in the case in June 2020. The appeal remains pending.

Other Matters

We are involved in various legal and administrative proceedings in the normal course of business, the ultimate resolutions of which, in the opinion of management, are not anticipated to have a material effect on our results of operations, liquidity or financial condition.

Labor Contracts

We employ certain personnel who are represented by labor unions, the terms of whose employment are governed by collective bargaining agreements. The terms of all current collective bargaining agreements covering represented personnel engaged in lignite mining operations, lignite-, coal- and nuclear-fueled generation operations and some of our natural gas-fueled generation operations expire on various dates between May 2021 and November 2023, but remain effective thereafter unless and until terminated by either party. We are also presently negotiating the terms of first contracts at two of our natural gas-fueled generation facilities. While we cannot predict the outcome of labor contract negotiations, we do not expect any negotiated terms in our new collective bargaining agreements or changes in our existing agreements to have a material adverse effect on our results of operations, liquidity or financial condition.

Nuclear Insurance

Nuclear insurance includes nuclear liability coverage, property damage, nuclear accident decontamination and accidental premature decommissioning coverage and accidental outage and/or extra expense coverage. We maintain nuclear insurance that meets or exceeds requirements promulgated by Section 170 (Price-Anderson) of the Atomic Energy Act (the Act) and Title 10 of the Code of Federal Regulations. We intend to maintain insurance against nuclear risks as long as such insurance is available. We are self-insured to the extent that losses (i) are within the policy deductibles, (ii) are not covered per policy exclusions, terms and limitations, (iii) exceed the amount of insurance maintained, or (iv) are not covered due to lack of insurance availability. Any such self-insured losses could have a material adverse effect on our results of operations, liquidity or financial condition.

With regard to nuclear liability coverage, the Act provides for financial protection for the public in the event of a significant nuclear generation plant incident. The Act sets the statutory limit of public liability for a single nuclear incident at $13.8 billion and requires nuclear generation plant operators to provide financial protection for this amount. However, the U.S. Congress could impose revenue-raising measures on the nuclear industry to pay claims that exceed the $13.8 billion limit for a single incident. As required, we insure against a possible nuclear incident at our Comanche Peak facility resulting in public nuclear-related bodily injury and property damage through a combination of private insurance and an industry-wide retrospective payment plan known as Secondary Financial Protection (SFP).

Under the SFP, in the event of any single nuclear liability loss in excess of $450 million at any nuclear generation facility in the U.S., each operating licensed reactor in the U.S. is subject to an annual assessment of up to $137.6 million. This approximately $137.6 million maximum assessment is subject to increases for inflation every five years, with the next expected adjustment scheduled to occur by November 2023. Assessments are currently limited to $20.5 million per operating licensed reactor per year per incident. As of December 31, 2020, our maximum potential assessment under the industry retrospective plan would be approximately $275 million per incident but no more than $41 million in any one year for each incident. The potential assessment is triggered by a nuclear liability loss in excess of $450 million per accident at any nuclear facility.
The United States Nuclear Regulatory Commission (NRC) requires that nuclear generation plant license holders maintain at least $1.06 billion of nuclear accident decontamination and reactor damage stabilization insurance, and requires that the proceeds thereof be used to place a plant in a safe and stable condition, to decontaminate a plant pursuant to a plan submitted to, and approved by, the NRC prior to using the proceeds for plant repair or restoration, or to provide for premature decommissioning. We maintain nuclear accident decontamination and reactor damage stabilization insurance for our Comanche Peak facility in the amount of $2.25 billion and non-nuclear accident related property damage in the amount of $1.0 billion (subject to a $5 million deductible per accident except for natural hazards which are subject to a $9.5 million deductible per accident), above which we are self-insured.

We also maintain Accidental Outage insurance to cover the additional costs of obtaining replacement electricity from another source if one or both of the units at our Comanche Peak facility are out of service for more than twelve weeks as a result of covered direct physical damage. Such coverage provides for weekly payments per unit up to $4.5 million for the first 52 weeks and up to $3.6 million for the remaining 71 weeks. The total maximum coverage is $328 million for non-nuclear property damage and $490 million for nuclear property damage. The coverage amounts applicable to each unit will be reduced to 80% if both units are out of service at the same time as a result of the same accident.
v3.20.4
Equity
12 Months Ended
Dec. 31, 2020
Stockholders' Equity Note [Abstract]  
Equity EQUITY
Equity Issuances and Repurchases

Changes in the number of shares of common stock issued and outstanding for the years ended December 31, 2020, 2019 and 2018 are reflected in the table below.
Shares
Issued
Treasury
Shares
Shares Outstanding
Balance at December 31, 2017428,398,802 — 428,398,802 
Shares issued (a) (b)97,639,105 — 97,639,105 
Shares retired(6,815)— (6,815)
Shares repurchased— (32,815,783)(32,815,783)
Balance at December 31, 2018526,031,092 (32,815,783)493,215,309 
Shares issued (a) (c)2,716,349 18,773,958 21,490,307 
Shares retired(6,106)— (6,106)
Shares repurchased— (27,001,399)(27,001,399)
Balance at December 31, 2019528,741,335 (41,043,224)487,698,111 
Shares issued (a)1,611,462 — 1,611,462 
Shares retired(3,685)— (3,685)
Balance at December 31, 2020530,349,112 (41,043,224)489,305,888 
____________
(a)Shares issued includes share awards granted to nonemployee directors.
(b)The year ended December 31, 2018 includes 94,409,573 shares issued in connection with the Merger (see Note 2).
(c)The year ended December 31, 2019 includes 18,773,958 treasury shares issued in connection with the settlement of all outstanding TEUs as discussed below.

Share Repurchase Programs

In September 2020, we announced that the Board authorized a new share repurchase program (Share Repurchase Program) under which up to $1.5 billion of our outstanding shares of common stock may be repurchased. The Share Repurchase Program was effective January 1, 2021, at which time the Prior Share Repurchase Plan (described below) and all authorized amounts remaining thereunder terminated as of such date.
Under the Share Repurchase Program, shares of the Company's common stock may be repurchased in open market transactions at prevailing market prices, in privately negotiated transactions, pursuant to plans complying with the Exchange Act, or by other means in accordance with federal securities laws. The actual timing, number and value of shares repurchased under the Share Repurchase Program or otherwise will be determined at our discretion and will depend on a number of factors, including our capital allocation priorities, the market price of our stock, general market and economic conditions, applicable legal requirements and compliance with the terms of our debt agreements.

In June 2018, we announced that the Board had authorized a share repurchase program under which up to $500 million of our outstanding common stock may be purchased, and this authorized amount was fully utilized in 2018. In November 2018, we announced that the Board had authorized an incremental share repurchase program under which up to $1.250 billion of our outstanding stock may be purchased, resulting in an aggregate $1.750 billion share repurchase program (collectively, Prior Share Repurchase Program). The Prior Share Repurchase Program was terminated on January 1, 2021. Shares of common stock repurchased under the Prior Share Repurchase Program for the years ended December 31, 2020, 2019 and 2018 are reflected in the table below.
$500 Million Board Authorization$1.250 Billion Board Authorization
Total Number of Shares RepurchasedAverage Price Paid ShareAmount Paid for Shares RepurchasedTotal Number of Shares RepurchasedAverage Price Paid ShareAmount Paid for Shares Repurchased
Year Ended December 31, 201821,421,925$23.36 $500 12,073,091$22.99 $278 
Year Ended December 31, 2019$— $— 26,322,166$24.34 $640 
Year Ended December 31, 2020— — — — 
Totals21,421,925$23.36 $500 38,395,257$23.91 $918 

Dividends

In November 2018, Vistra announced the Board adopted a dividend program which we initiated in the first quarter of 2019. Each dividend under the program will be subject to declaration by the Board and, thus, may be subject to numerous factors in existence at the time of any such declaration including, but not limited to, prevailing market conditions, Vistra's results of operations, financial condition and liquidity, Delaware law and any contractual limitations.

In February 2019, May 2019, July 2019 and October 2019, the Board declared quarterly dividends of $0.125 per share that were paid in March 2019, June 2019, September 2019 and December 2019, respectively.

In February 2020, April 2020, July 2020 and October 2020, the Board declared quarterly dividends of $0.135 per share that were paid in March 2020, June 2020, September 2020 and December 2020, respectively.

In February 2021, the Board declared a quarterly dividend of $0.15 per share that will be paid in March 2021.

Vistra did not declare or pay any dividends during the year ended December 31, 2018.

Dividend Restrictions

The Credit Facilities Agreement generally restricts the ability of Vistra Operations to make distributions to any direct or indirect parent unless such distributions are expressly permitted thereunder. As of December 31, 2020, Vistra Operations can distribute approximately $6.7 billion to Parent under the Credit Facilities Agreement without the consent of any party. The amount that can be distributed by Vistra Operations to Parent was partially reduced by distributions made by Vistra Operations to Parent of approximately $1.1 billion, $3.9 billion and $4.7 billion during the years ended December 31, 2020, 2019 and 2018, respectively. Additionally, Vistra Operations may make distributions to Parent in amounts sufficient for Parent to make any payments required under the TRA or the Tax Matters Agreement or, to the extent arising out of Parent's ownership or operation of Vistra Operations, to pay any taxes or general operating or corporate overhead expenses. As of December 31, 2020, the maximum amount of restricted net assets of Vistra Operations that may not be distributed to Parent totaled approximately $1.2 billion.

In addition to the restrictions under the Credit Facilities Agreement, under applicable Delaware law, we are only permitted to make distributions either out of "surplus," which is defined as the excess of our net assets above our capital (the aggregate par value of all outstanding shares of our stock), or out of net profits for the fiscal year in which the distribution is declared or the prior fiscal year.
Accumulated Other Comprehensive Income

During the years ended December 31, 2020, 2019 and 2018, we recorded changes in the funded status of our pension and other postretirement employee benefit liability totaling $23 million, $11 million and $9 million, respectively. During the years ended December 31, 2020, 2019 and 2018, $(5) million, $(3) million and $(3) million respectively was reclassified from accumulated other comprehensive income and reported in other deductions.

Warrants

At the Merger Date, the Company entered into an agreement whereby the holder of each outstanding warrant previously issued by Dynegy would be entitled to receive, upon paying an exercise, price of $35.00 (subject to adjustment from time to time), the number of shares of Vistra common stock that such holder would have been entitled to receive if it had held one share of Dynegy common stock at the closing of the Merger, or 0.652 shares of Vistra common stock. Accordingly, upon exercise, a warrant holder would effectively pay $53.68 (subject to adjustment of the exercise price from time to time) per share of Vistra common stock received. As of December 31, 2020, nine million warrants expiring in 2024 were outstanding. The warrants were included in equity based on their fair value at the Merger Date.

Tangible Equity Units (TEUs)

At the Merger Date, the Company assumed the obligations of Dynegy's 4,600,000 7.00% TEUs, each with a stated amount of $100.00 and each comprised of (i) a prepaid stock purchase contract that delivered to the holder on July 1, 2019, 4.0813 shares of Vistra common stock per contract with cash paid in lieu of any fractional shares at a rate of $22.5954 per share and (ii) a senior amortizing note with an outstanding principal amount of $38 million at the Merger Date that paid an equal quarterly cash installment of $1.75 per amortizing note (see Note 11). In the aggregate, the annual quarterly cash installments were equivalent to a 7.00% cash payment per year with respect to each $100.00 stated amount of TEUs. The amortizing notes were accounted for as debt while the stock purchase contract was included in equity based on the fair value of the contract at the Merger Date (see note 11). The entire class of TEUs were suspended from trading on the New York Stock Exchange on July 1, 2019 and removed from listing and registration on July 12, 2019. On July 1, 2019, approximately 18.8 million treasury shares of Vistra common stock were issued in connection with the settlement of all outstanding TEUs.
v3.20.4
Fair Value Measurements
12 Months Ended
Dec. 31, 2020
Fair Value Disclosures [Abstract]  
Fair Value Measurements FAIR VALUE MEASUREMENTS
We utilize several different valuation techniques to measure the fair value of assets and liabilities, relying primarily on the market approach of using prices and other market information for identical and/or comparable assets and liabilities for those items that are measured on a recurring basis. We use a mid-market valuation convention (the mid-point price between bid and ask prices) as a practical expedient to measure fair value for the majority of our assets and liabilities and use valuation techniques to maximize the use of observable inputs and minimize the use of unobservable inputs. Our valuation policies and procedures were developed, maintained and validated by a centralized risk management group that reports to the Vistra Chief Financial Officer.

Fair value measurements of derivative assets and liabilities incorporate an adjustment for credit-related nonperformance risk. These nonperformance risk adjustments take into consideration master netting arrangements, credit enhancements and the credit risks associated with our credit standing and the credit standing of our counterparties (see Note 16 for additional information regarding credit risk associated with our derivatives). We utilize credit ratings and default rate factors in calculating these fair value measurement adjustments.

We categorize our assets and liabilities recorded at fair value based upon the following fair value hierarchy:

Level 1 valuations use quoted prices in active markets for identical assets or liabilities that are accessible at the measurement date. Our Level 1 assets and liabilities include CME or ICE (electronic commodity derivative exchanges) futures and options transacted through clearing brokers for which prices are actively quoted. We report the fair value of CME and ICE transactions without taking into consideration margin deposits, with the exception of certain margin amounts related to changes in fair value on certain CME transactions that are legally characterized as settlement of derivative contracts rather than collateral.
Level 2 valuations utilize over-the-counter broker quotes, quoted prices for similar assets or liabilities that are corroborated by correlations or other mathematical means, and other valuation inputs such as interest rates and yield curves observable at commonly quoted intervals. We attempt to obtain multiple quotes from brokers that are active in the markets in which we participate and require at least one quote from two brokers to determine a pricing input as observable. The number of broker quotes received for certain pricing inputs varies depending on the depth of the trading market, each individual broker's publication policy, recent trading volume trends and various other factors.

Level 3 valuations use unobservable inputs for the asset or liability. Unobservable inputs are used to the extent observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. We use the most meaningful information available from the market combined with internally developed valuation methodologies to develop our best estimate of fair value. Significant unobservable inputs used to develop the valuation models include volatility curves, correlation curves, illiquid pricing delivery periods and locations and credit-related nonperformance risk assumptions. These inputs and valuation models are developed and maintained by employees trained and experienced in market operations and fair value measurements and validated by the Company's risk management group.

With respect to amounts presented in the following fair value hierarchy tables, the fair value measurement of an asset or liability (e.g., a contract) is required to fall in its entirety in one level, based on the lowest level input that is significant to the fair value measurement.

Assets and liabilities measured at fair value on a recurring basis consisted of the following at the respective balance sheet dates shown below:
December 31, 2020December 31, 2019
Level
1
Level
2
Level
3 (a)
Reclass (b)TotalLevel
1
Level
2
Level
3 (a)
Reclass (b)Total
Assets:
Commodity contracts$452 $201 $205 $76 $934 $1,047 $172 $239 $11 $1,469 
Interest rate swaps— 72 — — 72 — — — — — 
Nuclear decommissioning trust – equity securities (c)623 — — — 623 564 — — — 564 
Nuclear decommissioning trust – debt securities (c)— 618 — — 618 — 521 — — 521 
Sub-total$1,075 $891 $205 $76 2,247 $1,611 $693 $239 $11 2,554 
Assets measured at net asset value (d):
Nuclear decommissioning trust – equity securities (c)433 366 
Total assets$2,680 $2,920 
Liabilities:
Commodity contracts$578 $172 $183 $76 $1,009 $985 $439 $313 $11 $1,748 
Interest rate swaps— 404 — — 404 — 177 — — 177 
Total liabilities$578 $576 $183 $76 $1,413 $985 $616 $313 $11 $1,925 
____________
(a)See table below for description of Level 3 assets and liabilities.
(b)Fair values are determined on a contract basis, but certain contracts result in a current asset and a noncurrent liability, or vice versa, as presented in our consolidated balance sheets.
(c)The nuclear decommissioning trust investment is included in the other investments line in our consolidated balance sheets. See Note 21.
(d)The fair value amounts presented in this line are intended to permit reconciliation of the fair value hierarchy to the amounts presented in our consolidated balance sheets. Certain investments measured at fair value using the net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.

Commodity contracts consist primarily of natural gas, electricity, coal and emissions agreements and include financial instruments entered into for economic hedging purposes as well as physical contracts that have not been designated as normal purchases or sales. Interest rate swaps are used to reduce exposure to interest rate changes by converting floating-rate interest to fixed rates. See Note 16 for further discussion regarding derivative instruments.
Nuclear decommissioning trust assets represent securities held for the purpose of funding the future retirement and decommissioning of our nuclear generation facility. These investments include equity, debt and other fixed-income securities consistent with investment rules established by the NRC and the PUCT.

The following tables present the fair value of the Level 3 assets and liabilities by major contract type and the significant unobservable inputs used in the valuations at December 31, 2020 and 2019:
December 31, 2020
Fair Value
Contract Type (a)AssetsLiabilitiesTotalValuation TechniqueSignificant Unobservable InputRange (b)Average (b)
Electricity purchases and sales$61 $(90)$(29)Income ApproachHourly price curve shape (c)$— to$85 $43 
MWh
Illiquid delivery periods for hub power prices and heat rates (d)$25 to$125 $75 
MWh
Options38 (56)(18)Option Pricing ModelGas to power correlation (e)30 %to100 %64 %
Power and gas volatility (e)%to665 %336 %
Financial transmission rights92 (16)76 Market Approach (f)Illiquid price differences between settlement points (g)$(5)to$50 $22 
MWh
Other (h)14 (21)(7)
Total$205 $(183)$22 

December 31, 2019
Fair Value
Contract Type (a)AssetsLiabilitiesTotalValuation TechniqueSignificant Unobservable InputRange (b)Average (b)
Electricity purchases and sales$64 $(53)$11 Income ApproachHourly price curve shape (c)$— to$115 $58 
MWh
Illiquid delivery periods for ERCOT hub power prices and heat rates (d)$20 to$120 $70 
MWh
Options38 (188)(150)Option Pricing ModelGas to power correlation (e)10 %to100 %55 %
Power and gas volatility (e)%to440 %223 %
Financial transmission rights120 (26)94 Market Approach (f)Illiquid price differences between settlement points (g)$(10)to$40 $15 
MWh
Other (h)17 (46)(29)
Total$239 $(313)$(74)
____________
(a)Electricity purchase and sales contracts include power and heat rate positions in ERCOT, PJM, ISO-NE, NYISO and MISO regions. The forward purchase contracts (swaps and options) used to hedge electricity price differences between settlement points are referred to as congestion revenue rights (CRRs) in ERCOT and financial transmission rights (FTRs) in PJM, ISO-NE, NYISO and MISO regions. Options consist of physical electricity options, spread options, swaptions and natural gas options.
(b)The range of the inputs may be influenced by factors such as time of day, delivery period, season and location. The average represents the arithmetic average of the underlying inputs and is not weighted by the related fair value or notional amount.
(c)Primarily based on the historical range of forward average hourly ERCOT North Hub prices.
(d)Primarily based on historical forward ERCOT and PJM power prices and ERCOT heat rate variability.
(e)Primarily based on the historical forward correlation and volatility within ERCOT.
(f)While we use the market approach, there is insufficient market data to consider the valuation liquid.
(g)Primarily based on the historical price differences between settlement points within ERCOT hubs and load zones.
(h)Other includes contracts for natural gas, coal and environmental allowances.
There were no transfers between Level 1 and Level 2 of the fair value hierarchy for the years ended December 31, 2020, 2019 and 2018. See the table below for discussion of transfers between Level 2 and Level 3 for the years ended December 31, 2020, 2019 and 2018.

The following table presents the changes in fair value of the Level 3 assets and liabilities for the years ended December 31, 2020, 2019 and 2018.
Year Ended December 31,
202020192018
Net liability balance at beginning of period$(74)$(135)$(53)
Total unrealized valuation gains (losses)(5)(363)
Purchases, issuances and settlements (a):
Purchases164 176 146 
Issuances(28)(81)(41)
Settlements(90)(64)76 
Transfers into Level 3 (b)(2)10 
Transfers out of Level 3 (b)57 12 133 
Net liabilities assumed in connection with the Merger— — (37)
Net change (c)96 61 (82)
Net asset (liability) balance at end of period$22 $(74)$(135)
Unrealized valuation gains (losses) relating to instruments held at end of period$18 $(61)$(174)
____________
(a)Settlements reflect reversals of unrealized mark-to-market valuations previously recognized in net income. Purchases and issuances reflect option premiums paid or received, including CRRs and FTRs.
(b)Includes transfers due to changes in the observability of significant inputs. All Level 3 transfers during the periods presented are in and out of Level 2. For the year ended December 31, 2020, transfers out of Level 3 primarily consist of gas, power and coal derivatives where forward pricing inputs have become observable. For the years ended December 31, 2019 and 2018, transfers out of Level 3 primarily consist of power and coal derivatives where forward pricing inputs have become observable.
(c)Activity excludes change in fair value in the month positions settle. Substantially all changes in values of commodity contracts (excluding the net liabilities assumed in connection with the Merger) are reported as operating revenues in our consolidated statements of operations.
v3.20.4
Commodity And Other Derivative Contractual Assets And Liabilities
12 Months Ended
Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Commodity And Other Derivative Contractual Assets And Liabilities COMMODITY AND OTHER DERIVATIVE CONTRACTUAL ASSETS AND LIABILITIES
Strategic Use of Derivatives

We transact in derivative instruments, such as options, swaps, futures and forward contracts, to manage commodity price and interest rate risk. See Note 15 for a discussion of the fair value of derivatives.

Commodity Hedging and Trading Activity — We utilize natural gas and electricity derivatives to reduce exposure to changes in electricity prices primarily to hedge future revenues from electricity sales from our generation assets and to hedge future purchased power costs for our retail operations. We also utilize short-term electricity, natural gas, coal and emissions derivative instruments for fuel hedging and other purposes. Counterparties to these transactions include energy companies, financial institutions, electric utilities, independent power producers, fuel oil and gas producers, local distribution companies and energy marketing companies. Unrealized gains and losses arising from changes in the fair value of derivative instruments as well as realized gains and losses upon settlement of the instruments are reported in our consolidated statements of operations in operating revenues and fuel, purchased power costs and delivery fees.
Interest Rate Swaps — Interest rate swap agreements are used to reduce exposure to interest rate changes by converting floating-rate interest rates to fixed rates, thereby hedging future interest costs and related cash flows. Unrealized gains and losses arising from changes in the fair value of the swaps as well as realized gains and losses upon settlement of the swaps are reported in our consolidated statements of operations in interest expense and related charges. During 2019, Vistra entered into $2.12 billion of new interest rate swaps, pursuant to which Vistra will pay a variable rate and receive a fixed rate. The terms of these new swaps were matched against the terms of certain existing swaps, effectively offsetting the hedge of the existing swaps and fixing the out-of-the-money position of such swaps. These matched swaps will settle over time, in accordance with the original contractual terms. The remaining existing swaps continue to hedge our exposure on $2.30 billion of debt through July 2026.

Financial Statement Effects of Derivatives

Substantially all derivative contractual assets and liabilities are accounted for under mark-to-market accounting consistent with accounting standards related to derivative instruments and hedging activities. The following tables provide detail of derivative contractual assets and liabilities as reported in our consolidated balance sheets at December 31, 2020 and 2019. Derivative asset and liability totals represent the net value of the contract, while the balance sheet totals represent the gross value of the contract.
December 31, 2020
Derivative AssetsDerivative Liabilities
Commodity ContractsInterest Rate SwapsCommodity ContractsInterest Rate SwapsTotal
Current assets$665 $19 $64 $— $748 
Noncurrent assets197 53 — 258 
Current liabilities(1)— (717)(71)(789)
Noncurrent liabilities(3)— (288)(333)(624)
Net assets (liabilities)$858 $72 $(933)$(404)$(407)

December 31, 2019
Derivative AssetsDerivative Liabilities
Commodity ContractsInterest Rate SwapsCommodity ContractsInterest Rate SwapsTotal
Current assets$1,323 $— $10 $— $1,333 
Noncurrent assets136 — — — 136 
Current liabilities(1)— (1,510)(18)(1,529)
Noncurrent liabilities— — (237)(159)(396)
Net assets (liabilities)$1,458 $— $(1,737)$(177)$(456)

At December 31, 2020 and 2019, there were no derivative positions accounted for as cash flow or fair value hedges.

The following table presents the pretax effect of derivative gains (losses) on net income, including realized and unrealized effects. Amount represents changes in fair value of positions in the derivative portfolio during the period, as realized amounts related to positions settled are assumed to equal reversals of previously recorded unrealized amounts.

Year Ended December 31,
Derivative (consolidated statements of operations presentation)202020192018
Commodity contracts (Operating revenues)$241 $339 $(855)
Commodity contracts (Fuel, purchased power costs and delivery fees)(1)18 
Interest rate swaps (Interest expense and related charges)(196)(217)(11)
Net gain (loss)$49 $121 $(848)
Balance Sheet Presentation of Derivatives

We elect to report derivative assets and liabilities in our consolidated balance sheets on a gross basis without taking into consideration netting arrangements we have with counterparties to those derivatives. We maintain standardized master netting agreements with certain counterparties that allow for the right to offset assets and liabilities and collateral in order to reduce credit exposure between us and the counterparty. These agreements contain specific language related to margin requirements, monthly settlement netting, cross-commodity netting and early termination netting, which is negotiated with the contract counterparty.

Generally, margin deposits that contractually offset these derivative instruments are reported separately in our consolidated balance sheets, with the exception of certain margin amounts related to changes in fair value on CME transactions that are legally characterized as settlement of forward exposure rather than collateral. Margin deposits received from counterparties are primarily used for working capital or other general corporate purposes.

The following tables reconcile our derivative assets and liabilities on a contract basis to net amounts after taking into consideration netting arrangements with counterparties and financial collateral:
December 31, 2020December 31, 2019
Derivative Assets
and Liabilities
Offsetting Instruments (a)Cash Collateral (Received) Pledged (b)Net AmountsDerivative Assets
and Liabilities
Offsetting Instruments (a)Cash Collateral (Received) Pledged (b)Net Amounts
Derivative assets:
Commodity contracts$858 $(667)$(11)$180 $1,458 $(1,113)$— $345 
Interest rate swaps72 (72)— — — — — — 
Total derivative assets930 (739)(11)180 1,458 (1,113)— 345 
Derivative liabilities:
Commodity contracts(933)667 138 (128)(1,737)1,113 40 (584)
Interest rate swaps(404)72 — (332)(177)— — (177)
Total derivative liabilities(1,337)739 138 (460)(1,914)1,113 40 (761)
Net amounts$(407)$— $127 $(280)$(456)$— $40 $(416)
____________
(a)Amounts presented exclude trade accounts receivable and payable related to settled financial instruments.
(b)Represents cash amounts received or pledged pursuant to a master netting arrangement, including fair value-based margin requirements, and, to a lesser extent, initial margin requirements.
Derivative Volumes

The following table presents the gross notional amounts of derivative volumes at December 31, 2020 and 2019:
December 31, 2020December 31, 2019
Derivative typeNotional VolumeUnit of Measure
Natural gas (a)5,264 6,160 Million MMBtu
Electricity438,863 428,367 GWh
Financial transmission rights (b)217,350 199,648 GWh
Coal20 22 Million U.S. tons
Fuel oil176 33 Million gallons
Emissions20 Million tons
Renewable energy certificates18 11 Million certificates
Interest rate swaps – variable/fixed (c)$6,720 $6,720 Million U.S. dollars
Interest rate swaps - fixed/variable (c)$2,120 $2,120 Million U.S. dollars
____________
(a)Represents gross notional forward sales, purchases and options transactions, locational basis swaps and other natural gas transactions.
(b)Represents gross forward purchases associated with instruments used to hedge electricity price differences between settlement points within regions.
(c)Includes notional amounts of interest rate swaps with maturity dates through July 2026.

Credit Risk-Related Contingent Features of Derivatives

Our derivative contracts may contain certain credit risk-related contingent features that could trigger liquidity requirements in the form of cash collateral, letters of credit or some other form of credit enhancement. Certain of these agreements require the posting of collateral if our credit rating is downgraded by one or more credit rating agencies or include cross-default contractual provisions that could result in the settlement of such contracts if there was a failure under other financing arrangements related to payment terms or other covenants.

The following table presents the commodity derivative liabilities subject to credit risk-related contingent features that are not fully collateralized:
December 31,
20202019
Fair value of derivative contract liabilities (a)$(679)$(692)
Offsetting fair value under netting arrangements (b)262 167 
Cash collateral and letters of credit35 67 
Liquidity exposure$(382)$(458)
____________
(a)Excludes fair value of contracts that contain contingent features that do not provide specific amounts to be posted if features are triggered, including provisions that generally provide the right to request additional collateral (material adverse change, performance assurance and other clauses).
(b)Amounts include the offsetting fair value of in-the-money derivative contracts and net accounts receivable under master netting arrangements.

Concentrations of Credit Risk Related to Derivatives

We have concentrations of credit risk with the counterparties to our derivative contracts. At December 31, 2020, total credit risk exposure to all counterparties related to derivative contracts totaled $1.085 billion (including associated accounts receivable). The net exposure to those counterparties totaled $293 million at December 31, 2020 after taking into effect netting arrangements, setoff provisions and collateral, with the largest net exposure to a single counterparty totaling $85 million. At December 31, 2020, the credit risk exposure to the banking and financial sector represented 65% of the total credit risk exposure and 18% of the net exposure.
Exposure to banking and financial sector counterparties is considered to be within an acceptable level of risk tolerance because all of this exposure is with counterparties with investment grade credit ratings. However, this concentration increases the risk that a default by any of these counterparties would have a material effect on our financial condition, results of operations and liquidity. The transactions with these counterparties contain certain provisions that would require the counterparties to post collateral in the event of a material downgrade in their credit rating.

We maintain credit risk policies with regard to our counterparties to minimize overall credit risk. These policies authorize specific risk mitigation tools including, but not limited to, use of standardized master agreements that allow for netting of positive and negative exposures associated with a single counterparty. Credit enhancements such as parent guarantees, letters of credit, surety bonds, liens on assets and margin deposits are also utilized. Prospective material changes in the payment history or financial condition of a counterparty or downgrade of its credit quality result in the reassessment of the credit limit with that counterparty. The process can result in the subsequent reduction of the credit limit or a request for additional financial assurances. An event of default by one or more counterparties could subsequently result in termination-related settlement payments that reduce available liquidity if amounts are owed to the counterparties related to the derivative contracts or delays in receipts of expected settlements if the counterparties owe amounts to us.
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans
12 Months Ended
Dec. 31, 2020
Compensation and Retirement Benefits Disclosures [Abstract]  
Pension and Other Postretirement Employee Benefits (OPEB) Plans PENSION AND OTHER POSTRETIREMENT EMPLOYEE BENEFITS (OPEB) PLANS
Vistra is the plan sponsor of the Vistra Retirement Plan (the Retirement Plan), which provides benefits to eligible employees of its subsidiaries. Oncor is a participant in the Retirement Plan. As Vistra accounts for its interests in the Retirement Plan as a multiple employer plan, only Vistra's share of the plan assets and obligations are reported in the pension benefit information presented below. After amendments in 2012, employees in the Retirement Plan now consist entirely of participants who were active and retired collective bargaining unit employees. The Retirement Plan is a qualified defined benefit pension plan under Section 401(a) of the Internal Revenue Code of 1986, as amended (Code), and is subject to the provisions of ERISA. The Retirement Plan provides benefits to participants under one of two formulas: (i) a Cash Balance Formula under which participants earn monthly contribution credits based on their compensation and a combination of their age and years of service, plus monthly interest credits or (ii) a Traditional Retirement Plan Formula based on years of service and the average earnings of the three years of highest earnings. Under the Cash Balance Formula, future increases in earnings will not apply to prior service costs. It is our policy to fund the Retirement Plan assets only to the extent required under existing federal regulations.

Vistra and our participating subsidiaries offer other postretirement employee benefits (OPEB) in the form of certain health care and life insurance benefits to eligible retirees and their eligible dependents. The retiree contributions required for such coverage vary based on a formula depending on the retiree's age and years of service.

Prior to the Merger, Dynegy provided pension and OPEB benefits to certain of its employees and retirees. At the Merger Date, Vistra assumed these plans and the excess of the benefit obligations over the fair value of plan assets was recognized as a liability (see Note 2). Benefit obligations assumed totaled $539 million and the fair value of plan assets assumed totaled $459 million, and the net unfunded liability was recorded as $15 million to other noncurrent assets, $2 million to other current liabilities and $93 million to other noncurrent liabilities in the consolidated balance sheets.

Effective January 1, 2018, Vistra entered into a contractual arrangement with Oncor whereby the costs associated with providing OPEB coverage for certain retirees (Split Participants) whose employment included service with both the regulated businesses of Oncor (or its predecessors) and the non-regulated businesses of Vistra (or its predecessors) are split between Oncor and Vistra. As Vistra accounts for its interest in this OPEB plan as a multiple employer plan, only Vistra's share of the plan assets and obligations are reported in the OPEB information presented below. In addition, Vistra is the sponsor of OPEB plans that certain EFH Corp. and Dynegy retirees participate in.

Pension and OPEB Costs
Year Ended December 31,
202020192018
Pension costs$11 $$14 
OPEB costs11 
Total benefit costs recognized as expense$18 $20 $23 
Market-Related Value of Assets Held in Pension Benefit Trusts

We use the calculated value method to determine the market-related value of the assets held in the trust for purposes of calculating pension costs. We include all gains or losses in the market-related value of assets over a rolling four-year period. Each year, 25% of such gains and losses for the current year and for each of the preceding three years is included in the market-related value. Each year, the market-related value of assets is increased for contributions to the plan and investment income and is decreased for benefit payments and expenses for that year.

Detailed Information Regarding Pension Benefits

The following information is based on a December 31, 2020, 2019 and 2018 measurement dates:
Year Ended December 31,
202020192018
Assumptions Used to Determine Net Periodic Pension Cost:
Discount rate (Vistra Plan)3.24 %4.37 %3.74 %
Discount rate (Dynegy Plan and EEI Plan)3.24 %4.37 %4.05 %
Expected return on plan assets (Vistra Plan)4.44 %4.80 %4.56 %
Expected return on plan assets (Dynegy Plan)5.28 %5.31 %5.94 %
Expected return on plan assets (EEI Plan)5.45 %5.56 %4.74 %
Expected rate of compensation increase (Vistra Plan)3.29 %3.35 %3.62 %
Expected rate of compensation increase (Dynegy Plan and EEI Plan)3.29 %3.35 %3.50 %
Interest crediting rate for cash balance plans (Vistra Plan)3.50 %3.50 %3.50 %
Interest crediting rate for cash balance plans (Dynegy Plan and EEI Plan)3.50 %3.50 %4.25 %
Components of Net Pension Cost:
Service cost$$$15 
Interest cost20 25 21 
Expected return on assets(23)(26)(23)
Amortization of unrecognized amounts— — 
Immediate pension cost
Net periodic pension cost$11 $$14 
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income:
Net loss$17 $11 $14 
Total recognized in net periodic benefit cost and other comprehensive income$28 $20 $28 
Assumptions Used to Determine Benefit Obligations:
Discount rate2.50 %3.24 %4.37 %
Expected rate of compensation increase3.41 %3.29 %3.35 %
Interest crediting rate for cash balance plans3.00 %3.50 %3.50 %

For the year ended December 31, 2020, the net actuarial loss of $29 million was driven by losses attributable to decreasing discount rates due to changes in the corporate bond markets, actuarial assumption updates to reflect current market conditions and plan amendments, partially offset by gains attributable to actual asset performance exceeding expectations, life expectancy updates, annuity purchases, lump sum windows and plan experience different than expected.

For the year ended December 31, 2019, the net actuarial loss of $16 million was driven by losses attributable to decreasing discount rates due to changes in the corporate bond markets, actuarial assumption updates to reflect current market conditions, annuity purchases, plan amendments and plan experience different than expected, partially offset by gains attributable to actual asset performance exceeding expectations and life expectancy updates.

For the year ended December 31, 2018, the net actuarial loss of $14 million was driven by losses attributable to actual asset performance falling short of expectations and plan experience different than expected, partially offset by gains attributable to increasing discount rates due to changes in the corporate bond markets, economic assumption updates to reflect current market conditions and life expectancy projection updates.
Year Ended December 31,
20202019
Change in Pension Obligation:
Projected benefit obligation at beginning of period$674 $615 
Service cost
Interest cost20 25 
Lump-sum window(6)— 
Annuity purchase(29)(18)
Actuarial loss46 93 
Benefits paid(68)(48)
Projected benefit obligation at end of year$643 $674 
Accumulated benefit obligation at end of year$639 $669 
Change in Plan Assets:
Fair value of assets at beginning of period$528 $490 
Employer contributions16 — 
Lump-sum window(6)— 
Annuity purchase(29)(18)
Actual gain on assets40 102 
Benefits paid(64)(46)
Fair value of assets at end of year$485 $528 
Funded Status:
Projected pension benefit obligation$(643)$(674)
Fair value of assets485 528 
Funded status at end of year$(158)$(146)
Amounts Recognized in the Balance Sheet Consist of:
Other noncurrent liabilities$(158)$(146)
Net liability recognized$(158)$(146)
Amounts Recognized in Accumulated Other Comprehensive Income Consist of:
Net (loss)$(42)$(24)

The following table provides information regarding pension plans with projected benefit obligation (PBO) and accumulated benefit obligation (ABO) in excess of the fair value of plan assets.
December 31,
20202019
Pension Plans with PBO and ABO in Excess Of Plan Assets:
Projected benefit obligations$643 $674 
Accumulated benefit obligation$639 $669 
Plan assets$485 $528 
Pension Plan Investment Strategy and Asset Allocations

Our investment objective for the Retirement Plan is to invest in a suitable mix of assets to meet the future benefit obligations at an acceptable level of risk, while minimizing the volatility of contributions. Fixed income securities held primarily consist of corporate bonds from a diversified range of companies, U.S. Treasuries and agency securities and money market instruments. Equity securities are held to enhance returns by participating in a wide range of investment opportunities. International equity securities are used to further diversify the equity portfolio and may include investments in both developed and emerging markets. Real estate and credit strategies (primarily high yield bonds and emerging market debt) provide additional portfolio diversification and return potential.

The target asset allocation ranges of pension plan investments by asset category are as follows:
Target Allocation Ranges
Asset Category:Vistra PlanDynegy PlanEEI Plan
Fixed income65 %-75%45 %-55%40 %-50%
Global equity securities16 %-24%30 %-38%34 %-42%
Real estate%-8%%-12%10 %-14%
Credit strategies%-7%%-10%%-11%

Expected Long-Term Rate of Return on Assets Assumption

The Retirement Plan strategic asset allocation is determined in conjunction with the plan's advisors and utilizes a comprehensive Asset-Liability modeling approach to evaluate potential long-term outcomes of various investment strategies. The study incorporates long-term rate of return assumptions for each asset class based on historical and future expected asset class returns, current market conditions, rate of inflation, current prospects for economic growth, and taking into account the diversification benefits of investing in multiple asset classes and potential benefits of employing active investment management.
Retirement Plan
Expected Long-Term Rate of Return
Asset Class:Vistra PlanDynegy PlanEEI Plan
Fixed income securities2.4 %2.3 %2.3 %
Global equity securities7.3 %7.3 %7.3 %
Real estate5.6 %5.6 %5.6 %
Credit strategies4.8 %4.8 %4.8 %
Weighted average3.8 %4.4 %4.7 %

Fair Value Measurement of Pension Plan Assets

At December 31, 2020 and 2019, all of the Retirement Plan assets were measured at fair value using the net asset value per share (or its equivalent) and consisted of the following:
Year Ended December 31,
20202019
Asset Category:
Cash commingled trusts11 10 
Equity securities:
Global equities153 169 
Fixed income securities:
Corporate bonds (a)207 211 
Government bonds37 50 
Other (b)32 37 
Real estate45 51 
Total assets measured at net asset value$485 $528 
___________
(a)Substantially all corporate bonds are rated investment grade by a major ratings agency such as Moody's.
(b)Consists primarily of high-yield bonds, emerging market debt and bank loans.
Detailed Information Regarding Postretirement Benefits Other Than Pensions

The following OPEB information is based on a December 31, 2020 measurement date:
Year Ended December 31,
202020192018
Assumptions Used to Determine Net Periodic Benefit Cost:
Discount rate (Vistra Plan)3.25 %4.35 %3.67 %
Discount rate (Split-Participant Plan)3.25 %4.35 %3.67 %
Discount rate (Dynegy Plan)3.25 %4.35 %4.04 %
Expected return on plan assets (EEI Union)7.07 %5.36 %5.10 %
Expected return on plan assets (EEI Salaried)3.43 %4.70 %4.47 %
Components of Net Postretirement Benefit Cost:
Service cost$$$
Interest cost
Expected return on plan assets(2)(1)(1)
Amortization of unrecognized amounts
Immediate postretirement benefit cost(1)— 
Net periodic OPEB cost$$11 $
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income:
Net (gain) loss and prior service (credit) cost$$— $(6)
Total recognized in net periodic benefit cost and other comprehensive income$12 $11 $
Assumptions Used to Determine Benefit Obligations at Period End:
Discount rate2.51 %3.25 %4.35 %

For the year ended December 31, 2020, the net actuarial loss of $10 million was driven by losses attributable to decreasing discount rates due to changes in the corporate bond markets and plan experience different than expected, partially offset by gains attributable to actual asset performance exceeding expectations, life expectancy updates and updates to health care claims and trend assumptions.

For the year ended December 31, 2019, the net actuarial loss of $5 million was driven by losses attributable to decreasing discount rates due to changes in the corporate bond markets and plan experience different than expected, partially offset by gains attributable to actual asset performance exceeding expectations, life expectancy changes, updates to health care related assumptions and changes due to the repeal of certain Affordable Care Act fees.

For the period ended December 31, 2018, the net actuarial loss of $7 million was driven by gains attributable to increasing discount rates due to changes in the corporate bond markets, life expectancy projection updates and updates to health care related assumptions, partially offset by losses attributable to actual asset performance falling short of expectations and plan experience different than expected.
Year Ended December 31,
20202019
Change in Postretirement Benefit Obligation:
Benefit obligation at beginning of year$151 $144 
Service cost
Interest cost
Participant contributions
Actuarial loss12 10 
Benefits paid(15)(14)
Benefit obligation at end of year$157 $151 
Change in Plan Assets:
Fair value of assets at beginning of year$34 $29 
Employer contributions
Participant contributions
Benefits paid(13)(13)
Actual gain on assets
Fair value of assets at end of year$37 $34 
Funded Status:
Benefit obligation$(157)$(151)
Fair value of assets37 34 
Funded status at end of year$(120)$(117)
Amounts Recognized on the Balance Sheet Consist of:
Other noncurrent assets$23 $18 
Other current liabilities$(9)$(9)
Other noncurrent liabilities(134)(126)
Net liability recognized$(120)$(117)
Amounts Recognized in Accumulated Other Comprehensive Income Consist of:
Net loss and prior service cost$20 $15 

The following tables provide information regarding the assumed health care cost trend rates.
December 31, 2020December 31, 2019
Assumed Health Care Cost Trend Rates-Not Medicare Eligible:
Health care cost trend rate assumed for next year6.20 %6.40 %
Rate to which the cost trend is expected to decline (the ultimate trend rate)4.50 %4.50 %
Year that the rate reaches the ultimate trend rate20292029
Assumed Health Care Cost Trend Rates-Medicare Eligible:
Health care cost trend rate assumed for next year (Vistra Plan, EEI Union and EEI Salaried)9.10 %8.60 %
Health care cost trend rate assumed for next year (Split-Participant Plan)8.80 %8.30 %
Rate to which the cost trend is expected to decline (the ultimate trend rate)4.50 %4.50 %
Year that the rate reaches the ultimate trend rate20302029

Fair Value Measurement of OPEB Plan Assets

At December 31, 2020 and 2019, the Vistra OPEB plan assets measured at fair value on a recurring basis totaled $37 million and $34 million, respectively, and consisted of $29 million and $26 million, respectively, of U.S. equities classified as Level 1 and $8 million and $8 million, respectively, of U.S. Treasuries and municipal bonds classified as Level 2.
Significant Concentrations of Risk

The plans' investments are exposed to risks such as interest rate, capital market and credit risks. We seek to optimize return on investment consistent with levels of liquidity and investment risk which are prudent and reasonable, given prevailing capital market conditions and other factors specific to us. While we recognize the importance of return, investments will be diversified in order to minimize the risk of large losses unless, under the circumstances, it is clearly prudent not to do so. There are also various restrictions and guidelines in place including limitations on types of investments allowed and portfolio weightings for certain investment securities to assist in the mitigation of the risk of large losses.

Assumed Discount Rate

We selected the assumed discount rates using the Aon AA Above Median yield curve, which is based on corporate bond yields and at December 31, 2020 consisted of 305 corporate bonds with an average rating of AA using Moody's, S&P and Fitch ratings.

Contributions

Contributions to the Retirement Plan for the years ended December 31, 2020, 2019 and 2018 totaled $16 million, zero and $12 million, respectively, and $1 million in contributions are expected to be made in 2021. OPEB plan funding for the years ended December 31, 2020, 2019 and 2018 totaled $9 million, $9 million and $8 million, respectively, and funding in 2021 is expected to total $9 million.

Future Benefit Payments

Estimated future benefit payments to beneficiaries are as follows:
202120222023202420252026-2030
Pension benefits$49 $43 $43 $40 $52 $188 
OPEB$10 $10 $10 $10 $$41 

Qualified Savings Plans

Our employees may participate in a qualified savings plan (the Thrift Plan). This plan is a participant-directed defined contribution plan intended to qualify under Section 401(a) of the Code and is subject to the provisions of ERISA. Under the terms of the Thrift Plan, employees who do not earn more than the IRS threshold compensation limit used to determine highly compensated employees may contribute, through pre-tax salary deferrals and/or after-tax payroll deductions, the lesser of 75% of their regular salary or wages or the maximum amount permitted under applicable law. Employees who earn more than such threshold may contribute from 1% to 20% of their regular salary or wages. Employer matching contributions are also made in an amount equal to 100% (75% for employees covered under the traditional formula in the Retirement Plan) of the first 6% of employee contributions. Employer matching contributions are made in cash and may be allocated by participants to any of the plan's investment options.

At the Merger Date, Vistra assumed Dynegy's participant-directed defined contribution plan. In January 2019, this plan was merged into the Thrift Plan.

Aggregate employer contributions to the qualified savings plans totaled $34 million, $27 million and $24 million for the years ended December 31, 2020, 2019 and 2018, respectively.
v3.20.4
Stock-Based Compensation (Notes)
12 Months Ended
Dec. 31, 2020
Share-based Payment Arrangement [Abstract]  
Stock-Based Compensation STOCK-BASED COMPENSATION
Vistra 2016 Omnibus Incentive Plan

On the Effective Date, the Vistra board of directors (Board) adopted the 2016 Omnibus Incentive Plan (2016 Incentive Plan), under which an aggregate of 22,500,000 shares of our common stock were reserved for issuance as equity-based awards to our non-employee directors, employees, and certain other persons. Following approval of the Board and approval by the stockholders at the 2019 annual meeting of the Company, the 2016 Incentive Plan was amended to increase the maximum number of shares reserved for issuance under the 2016 Incentive Plan to 37,500,000. The Board or any committee duly authorized by the Board will administer the 2016 Incentive Plan and has broad authority under the 2016 Incentive Plan to, among other things: (a) select participants, (b) determine the types of awards that participants are to receive and the number of shares that are to be subject to such awards and (c) establish the terms and conditions of awards, including the price (if any) to be paid for the shares of the award. The types of awards that may be granted under the 2016 Incentive Plan include stock options, RSUs, restricted stock, performance awards and other forms of awards granted or denominated in shares of Vistra common stock, as well as certain cash-based awards.

If any stock option or other stock-based award granted under the 2016 Incentive Plan expires, terminates or is canceled for any reason without having been exercised in full, the number of shares of Vistra common stock underlying any unexercised award shall again be available for awards under the 2016 Incentive Plan. If any shares of restricted stock, performance awards or other stock-based awards denominated in shares of Vistra common stock awarded under the 2016 Incentive Plan are forfeited for any reason, the number of forfeited shares shall again be available for purposes of awards under the 2016 Incentive Plan. Any award under the 2016 Incentive Plan settled in cash shall not be counted against the maximum share limitation. No awards under the 2016 Incentive Plan have been settled in cash since the Effective Date.

As is customary in incentive plans of this nature, each share limit and the number and kind of shares available under the 2016 Incentive Plan and any outstanding awards, as well as the exercise or purchase price of awards, and performance targets under certain types of performance-based awards, are required to be adjusted in the event of certain reorganizations, mergers, combinations, recapitalizations, stock splits, stock dividends or other similar events that change the number or kind of shares outstanding, and extraordinary dividends or distributions of property to the Vistra stockholders.

Assumption of Dynegy Stock Compensation Plans

At the Merger Date, Dynegy stock options and equity-based awards outstanding immediately prior to the Merger Date were generally automatically converted upon completion of the Merger into stock options and equity-based awards, respectively, with respect to Vistra's common stock, after giving effect to the Exchange Ratio.
Instrument TypeDynegy Awards Prior to the Merger DateVistra Awards Converted at the Merger DateFair Value of Awards (a) at the Merger Date
Stock Options4,096,027 2,670,610 $10 
Restricted Stock Units5,718,148 3,056,689 61 
Performance Units1,538,133 938,721 18 
Total$89 
____________
(a)$26 million was attributable to pre-combination service and considered part of the purchase price (see Note 2). $33 million was recognized immediately as compensation expense due to accelerated vesting as a result of the Merger. $30 million will be amortized as compensation expense over the remaining service period and is recorded in additional paid in capital in the consolidated balance sheet.

Stock-Based Compensation Expense

Stock-based compensation expense is reported as SG&A in the consolidated statements of operations as follows:
Year Ended December 31,
202020192018
Total stock-based compensation expense$63 $47 $73 
Income tax benefit(15)(9)(15)
Stock based-compensation expense, net of tax$48 $38 $58 
Stock Options

The fair value of each stock option is estimated on the date of grant using a Black-Scholes option-pricing model. The risk-free interest rate used in the option valuation model was based on yields available on the grant dates for U.S. Treasury Strips with maturity consistent with the expected life assumption. The expected term of the option represents the period of time that options granted are expected to be outstanding and is based on the SEC Simplified Method (midpoint of average vesting time and contractual term). Expected volatility is based on an average of the historical, daily volatility of a peer group selected by Vistra over a period consistent with the expected life assumption ending on the grant date. We assumed no dividend yield in the valuation of the options granted from 2016 through 2018, and assumed 2.3% and 1.9% dividend yields in the valuation of options granted in 2020 and 2019, respectively. These options may be exercised over either three- or four-year graded vesting periods and will expire 10 years from the grant date.

Issuance of Merger-related Stock Options At the Merger Date, we issued 5.2 million stock options to certain members of management, which are subject to performance and service conditions for vesting. The performance condition is based on the Company's achievement of certain merger related targets which were achieved as of December 31, 2019. Compensation cost was recognized in 2018, 2019 and 2020 based on graded vesting over 4 and 5 years since the date of issuance because we estimated achievement of the target was likely to occur.

Stock options outstanding at December 31, 2020 are all held by current or former employees. The following table summarizes our stock option activity:
Year Ended December 31, 2020
Stock Options
(in thousands)
Weighted
Average Exercise Price
Weighted Average Remaining Contractual Term (Years)Aggregate Intrinsic Value (in millions)
Total outstanding at beginning of period13,535 $18.73 7.3$69.3 
Granted3,014 $22.98 
Exercised(251)$13.62 
Forfeited or expired(268)$20.74 
Total outstanding at end of period16,030 $19.58 6.7$30.8 
Exercisable at December 31, 20206,871 $16.83 5.9$30.5 

At December 31, 2020, $27 million of unrecognized compensation cost related to unvested stock options granted under the 2016 Incentive Plan are expected to be recognized over a weighted average period of approximately 2 years.

Restricted Stock Units

The following table summarizes our restricted stock unit activity:
Year Ended December 31, 2020
Restricted Stock Units
(in thousands)
Weighted
Average Grant Date Fair Value
Total nonvested at beginning of period2,538 $20.99 
Granted1,209 $22.50 
Vested(1,456)$19.48 
Forfeited(39)$21.89 
Total nonvested at end of period2,252 $22.35 

At December 31, 2020, $27 million of unrecognized compensation cost related to unvested restricted stock units granted under the 2016 Incentive Plan are expected to be recognized over a weighted average period of approximately 2 years.
Performance Stock Units

In October 2017, February 2019 and February 2020, we issued Performance Stock Units (PSUs) to certain members of management. All PSUs have a three years performance period and a payout opportunity of 0-200% of target (100%), which is intended to be settled in shares of Vistra common stock. As of December 31, 2019, we had not yet established the final terms of the previously issued PSUs relevant to vesting (scorecard, thresholds, and targets) for the entire measurement period; therefore, a grant date for financial accounting purposes had not occurred. In February 2020, the final terms were established for the October 2017 issuance and a grant date for financial accounting purposes had occurred. In March 2020, we began recognizing compensation cost ratably over the remaining 13-month vesting period for the October 2017 issuance. In February 2021, the final terms were established for the February 2019 issuance and a grant date for financial accounting purposes has occurred. In March 2021, we will begin recognizing compensation cost ratably over the remaining 12-month vesting period for the February 2019 issuance. Additional PSUs were issued to certain members of management in February 2021 with the grant date for accounting purposes not yet established. The following table summarizes our PSU activity:
Year Ended December 31, 2020
Performance Stock Units
(in thousands)
Weighted
Average Grant Date Fair Value
Total nonvested at beginning of period— $— 
Granted473 $23.43 
Vested(21)$23.43 
Forfeited(1)$23.43 
Total nonvested at end of period451 $23.43 

At December 31, 2020, $4 million of unrecognized compensation cost related to unvested performance stock units granted under the 2016 Incentive Plan is expected to be recognized over a weighted average period of approximately 3 months.
v3.20.4
Related Party Transactions
12 Months Ended
Dec. 31, 2020
Related Party Transactions [Abstract]  
Related Party Transactions RELATED PARTY TRANSACTIONS
In connection with Emergence, we entered into agreements with certain of our affiliates and with parties who received shares of common stock and TRA Rights in exchange for their claims.

Registration Rights Agreement

Pursuant to the Plan of Reorganization, on the Effective Date, we entered into a Registration Rights Agreement (the Registration Rights Agreement) with certain selling stockholders providing for registration of the resale of the Vistra common stock held by such selling stockholders.

In December 2016, we filed a Form S-1 registration statement with the SEC to register for resale the shares of Vistra common stock held by certain significant stockholders pursuant to the Registration Rights Agreement, which was declared effective by the SEC in May 2017. The registration statement was amended in March 2018. Pursuant to the Registration Rights Agreement, in June 2018, we filed a post-effective amendment to the Form S-1 registration statement on Form S-3, which was declared effective by the SEC in July 2018. Among other things, under the terms of the Registration Rights Agreement:

if we propose to file certain types of registration statements under the Securities Act with respect to an offering of equity securities, we will be required to use our reasonable best efforts to offer the other parties to the Registration Rights Agreement the opportunity to register all or part of their shares on the terms and conditions set forth in the Registration Rights Agreement; and

the selling stockholders received the right, subject to certain conditions and exceptions, to request that we file registration statements or amend or supplement registration statements, with the SEC for an underwritten offering of all or part of their respective shares of Vistra common stock (a Demand Registration), and the Company is required to cause any such registration statement or amendment or supplement (a) to be filed with the SEC promptly and, in any event, on or before the date that is 45 days, in the case of a registration statement on Form S-1, or 30 days, in the case of a registration statement on Form S-3, after we receive the written request from the relevant selling stockholders to effectuate the Demand Registration (as defined in the Registration Rights Agreement) and (b) to become effective as promptly as reasonably practicable and in any event no later than 120 days after it is initially filed.

All expenses of registration under the Registration Rights Agreement, including the legal fees of one counsel retained by or on behalf of the selling stockholders, will be paid by us. Legal fee expenses paid or accrued by Vistra on behalf of the selling stockholders totaled less than $1 million during each of the years ended December 31, 2020, 2019 and 2018.

Tax Receivable Agreement

On the Effective Date, Vistra entered into the TRA with a transfer agent on behalf of certain former first-lien creditors of TCEH. See Note 8 for discussion of the TRA.

Share Repurchase Transaction

In November 2018, the disinterested members of the Board considered and approved (in accordance with the Company's corporate governance guidelines) a share repurchase transaction, whereby Apollo Management Holdings L.P. (Apollo) and the Company, in a privately negotiated transaction, agreed for the Company to directly repurchase 5 million of Vistra common shares from Apollo. This purchase was part of Apollo's larger, 17 million share block trade, with the remaining 12 million shares being sold in a separate unregistered Rule 144 secondary block trade to a broker-dealer, who placed all 12 million shares with institutional investors. The Company repurchased the 5 million shares at the same discounted price (discounted from the November 19, 2018 closing price) that the participating broker paid for the 12 million shares it purchased, and the Company did not pay any additional fees to Apollo or the participating broker for the 5 million shares it repurchased.
v3.20.4
Segment Information
12 Months Ended
Dec. 31, 2020
Segment Reporting [Abstract]  
Segment Information SEGMENT INFORMATION
The operations of Vistra are aligned into six reportable business segments: (i) Retail, (ii) Texas, (iii) East, (iv) West, (v) Sunset and (vi) Asset Closure. In the third quarter of 2020, Vistra updated its reportable segments to reflect changes in how the Company's Chief Operating Decision Maker (CODM) makes operating decisions, assesses performance and allocates resources. Management believes the revised reportable segments provide enhanced transparency into the Company's long-term sustainable assets and its commitment to managing the retirement of economically and environmentally challenged plants. The following is a summary of the updated segments:

The Sunset segment represents plants with announced retirement plans that were previously reported in the ERCOT, PJM and MISO segments. As we announced significant plant closures in the third quarter of 2020, management believes it is important to have a segment which differentiates between operating plants with defined retirement plans and operating plants without defined retirement plans.
The East segment represents Vistra's electricity generation operations in the Eastern Interconnection of the U.S. electric grid, other than assets that are now part of the Sunset or Asset Closure segments, respectively, and includes operations in PJM, ISO-NE and NYISO that were previously reported in the PJM and NY/NE segments, respectively.
The West segment represents Vistra's electricity generation operations in CAISO and was previously reported in the Corporate and Other non-segment. As reflected by the Moss Landing and Oakland ESS projects (see Note 3), the Company expects to expand its operations in the West segment.

Our CODM reviews the results of these segments separately and allocates resources to the respective segments as part of our strategic operations. A measure of assets is not applicable, as segment assets are not regularly reviewed by the CODM for evaluating performance or allocating resources.

The Retail segment is engaged in retail sales of electricity and natural gas to residential, commercial and industrial customers. Substantially all of these activities are conducted by TXU Energy, Ambit, Value Based Brands, Dynegy Energy Services, Homefield Energy, TriEagle Energy, Public Power and U.S. Gas & Electric across 19 states in the U.S.

The Texas and East segments are engaged in electricity generation, wholesale energy sales and purchases, commodity risk management activities, fuel production and fuel logistics management. The Texas segment represents results from the ERCOT market and was referred to as the ERCOT segment prior to the third quarter of 2020. The East segment represents results from the PJM, ISO-NE and NYISO markets. We determined it was appropriate to aggregate results from these markets into one reportable segment, East, given similar economic characteristics.

The West segment represents results from the CAISO market, including our development of battery ESS projects at our Moss Landing and Oakland power plant sites (see Note 3).

The Sunset segment consists of generation plants with announced retirement plans. Separately reporting the Sunset segment differentiates operating plants with announced retirement plans from our other operating plants in the Texas, East and West segments. We have allocated unrealized gains and losses on the commodity risk management activities to the Sunset segment for the generation plants that have announced retirement plans.

The Asset Closure segment is engaged in the decommissioning and reclamation of retired plants and mines (see Note 4). Separately reporting the Asset Closure segment provides management with better information related to the performance and earnings power of Vistra's ongoing operations and facilitates management's focus on minimizing the cost associated with decommissioning and reclamation of retired plants and mines. We have not allocated any unrealized gains or losses on the commodity risk management activities to the Asset Closure segment for the generation plants that were retired in 2018, 2019 and 2020.

Corporate and Other represents the remaining non-segment operations consisting primarily of general corporate expenses, interest, taxes and other expenses related to our support functions that provide shared services to our operating segments.

Except as noted in Note 1, the accounting policies of the business segments are the same as those described in the summary of significant accounting policies in Note 1. Our CODM uses more than one measure to assess segment performance, including segment net income (loss), which is the measure most comparable to consolidated net income (loss) prepared based on U.S. GAAP. We account for intersegment sales and transfers as if the sales or transfers were to third parties, that is, at market prices. Certain shared services costs are allocated to the segments.

For the year ended
RetailTexasEastWestSunsetAsset ClosureCorporate and Other (b)EliminationsConsolidated
Operating revenues (a):
December 31, 2020$8,270 $4,116 $2,415 $282 $1,252 $$— $(4,895)$11,443 
December 31, 20196,872 3,836 2,790 338 1,602 341 — (3,970)11,809 
December 31, 20185,597 2,497 1,895 208 1,183 371 — (2,607)9,144 
Depreciation and amortization:
December 31, 2020$(303)$(475)$(721)$(19)$(133)$(22)$(64)$— $(1,737)
December 31, 2019(292)(472)(680)(19)(120)— (57)— (1,640)
December 31, 2018(318)(390)(519)(14)(81)— (72)— (1,394)
Operating income (loss):
December 31, 2020$312 $1,761 $73 $39 $(420)$(109)$(137)$— $1,519 
December 31, 2019155 1,314 398 88 271 (107)(127)1,993 
December 31, 2018690 (103)10 35 242 (63)(320)— 491 
Interest expense and related charges:
December 31, 2020$(10)$$(7)$10 $(2)$— $(632)$$(630)
December 31, 2019(21)(13)— (4)— (770)(797)
December 31, 2018(7)(12)(10)(1)(1)— (612)71 (572)
Income tax (expense) benefit:
December 31, 2020$— $— $— $— $— $— $(266)$— $(266)
December 31, 2019— — — — — — (290)— (290)
December 31, 2018— — — — — — 45 — 45 
Net income (loss):
December 31, 2020$309 $1,760 $41 $50 $(414)$(101)$(1,021)$— $624 
December 31, 2019134 1,342 400 88 274 (109)(1,204)926 
December 31, 2018712 (88)18 34 242 (62)(912)— (56)
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures:
December 31, 2020$$388 $71 $$46 $— $91 $— $600 
December 31, 2019296 61 58 — 69 — 487 
December 31, 2018280 21 36 — 50 — 396 
____________
(a)The following unrealized net gains (losses) from mark-to-market valuations of commodity positions are included in operating revenues:
For the year endedRetailTexasEastWestSunsetAsset ClosureCorporate and OtherEliminations (1)Consolidated
December 31, 2020$(11)$677 $(23)$(10)$(140)$— $— $(329)$164 
December 31, 2019575 195 41 168 — — (305)682 
December 31, 2018(12)(483)(76)(15)(11)— — 217 (380)
____________
(1) Amounts offset in fuel, purchased power costs and delivery fees in the Retail segment, with no impact to consolidated results.
(b)Income tax expense is not reflected in net income of the segments but is reflected entirely in Corporate and Other net income.
v3.20.4
Supplementary Financial Information
12 Months Ended
Dec. 31, 2020
Supplementary Financial Information [Abstract]  
Supplementary Financial Information SUPPLEMENTARY FINANCIAL INFORMATION
Impairment of Long-Lived Assets

In the third quarter of 2020, we recognized impairment losses of $173 million related to our Kincaid coal generation facility in Illinois and $99 million related to our Zimmer coal generation facility in Ohio, each as a result of a significant decrease in the estimated useful life of the facility, reflecting our recently announced plan to retire both facilities by the end of 2027 in response to the final CCR rule (see Notes 4 and 13). The impairment losses are reported in our Sunset segment and include a $260 million write-down of property, plant and equipment and a $12 million write-down of inventory. In determining the fair value of the impaired assets, we equally weighted a market approach valuation based on transactions of similar assets and an income approach valuation discounting our projected cash flows through the respective plant retirement dates.

In the first quarter of 2020, we recognized an impairment loss of $52 million related to our Joppa/EEI coal generation facility in Illinois as a result of a significant decrease in the estimated useful life of the facility, reflecting a decrease in the economic forecast of the facility and changes to the operating assumption based on lower forecasted wholesale electricity prices. We also recorded a $32 million impairment to a capacity contract which was linked in part to the Joppa/EEI facility and therefore determined to have a significant decrease in estimated useful life. The impairments are reported in our Sunset segment and include a $45 million write-down of property, plant and equipment, a $32 million write-down of intangible assets and a $7 million write-down of inventory.

Interest Expense and Related Charges
Year Ended December 31,
202020192018
Interest paid/accrued$467 $576 $537 
Unrealized mark-to-market net losses on interest rate swaps155 220 
Amortization of debt issuance costs, discounts and premiums18 — 
Debt extinguishment (gain) loss(17)(21)27 
Capitalized interest(21)(12)(12)
Other28 25 15 
Total interest expense and related charges$630 $797 $572 

The weighted average interest rate applicable to the Vistra Operations Credit Facilities, taking into account the interest rate swaps discussed in Note 11, was 3.88%, 4.03% and 4.24% at December 31, 2020, 2019 and 2018, respectively.
Other Income and Deductions
Year Ended December 31,
202020192018
Other income:
Insurance settlement (a)$$22 $16 
Funds released from escrow to settle pre-petition claims of our predecessor (b)— — 
Office space sublease rental income (b)— — 
Sale of land (c)— 
Interest income10 18 
All other18 15 
Total other income$34 $56 $47 
Other deductions:
Loss on disposal of investment in NELP (d)$29 $— $— 
All other13 15 
Total other deductions$42 $15 $
____________
(a)For the year ended December 31, 2020, $3 million reported in the Corporate and Other non-segment, $2 million reported in the Asset Closure segment and $1 million reported in the Texas segment. The amounts for the years ended December 31, 2019 and 2018, respectively, are reported in the Texas segment.
(b)Reported in the Corporate and Other non-segment. Beginning January 1, 2019, our office space sublease rental income related to real estate leases is reported in SG&A expenses in the consolidated statements of operations.
(c)For the year ended December 31, 2020, reported in the Asset Closure segment. For the year ended December 31, 2018, reported in the Texas segment.
(d)Reported in the East segment.

Restricted Cash
December 31, 2020December 31, 2019
Current
Assets
Noncurrent AssetsCurrent
Assets
Noncurrent Assets
Amounts related to remediation escrow accounts$19 $19 $15 $28 
Amounts related to restructuring escrow accounts— — 43 — 
Amounts related to Ambit customer deposits— — 19 — 
Amounts related to Ambit commodity trading agreement— — 62 — 
Amounts related to Ambit letters of credit (Note 11)— — — 
Total restricted cash$19 $19 $147 $28 

Remediation Escrow During the years ended December 31, 2020 and 2019, Vistra transferred asset retirement obligations related to several closed plant sites to a third-party remediation company. As part of certain transfers, Vistra deposits funds into an escrow accounts, and the funds are released to the remediation company as milestones are reached in the remediation process. Amounts contractually payable to the third party in exchange for assuming the obligations are included in other current liabilities and other noncurrent liabilities and deferred credits.

Pre-Petition Claims — On the Effective Date, the TCEH Debtors (together with the Contributed EFH Debtors) emerged from the Chapter 11 Cases and discharged approximately $33.8 billion in liabilities subject to compromise. Initial distributions related to the allowed claims asserted against the TCEH Debtors and the Contributed EFH Debtors commenced subsequent to the Effective Date. Amounts were held in escrow to (1) distribute to holders of contingent and/or disputed unsecured claims that become allowed and/or (2) make distributions to holders of previously allowed unsecured claims, if applicable. In December 2019, the Bankruptcy Court entered an order, Docket No. 13982, sustaining the TCEH Debtors' objection to and liquidating the manifested and unmanifested asbestos claims. As of this filing, the TCEH Debtors believe they have resolved the remaining contingent and/or disputed unsecured claims, and have undertook the necessary steps to modify the claims register accordingly and made final distribution from the escrow to holders of allowed claims. At December 31, 2019, unresolved claims were recorded in Vistra's consolidated balance sheet as other current liabilities, and the related escrow balance were recorded in Vistra's consolidated balance sheet as current restricted cash. All non-priority unsecured claims, including asbestos claims arising before the Petition Date, were satisfied solely from the amounts in escrow.
Trade Accounts Receivable
December 31,
20202019
Wholesale and retail trade accounts receivable$1,324 $1,401 
Allowance for uncollectible accounts(45)(36)
Trade accounts receivable — net$1,279 $1,365 

Gross trade accounts receivable at December 31, 2020 and 2019 included unbilled retail revenues of $468 million and $494 million, respectively.

Allowance for Uncollectible Accounts Receivable
Year Ended December 31,
202020192018
Allowance for uncollectible accounts receivable at beginning of period (a)$42 $19 $14 
Increase for bad debt expense110 82 56 
Decrease for account write-offs(107)(65)(51)
Allowance for uncollectible accounts receivable at end of period$45 $36 $19 
____________
(a)Includes a $6 million increase recorded due to the adoption of ASU 2016-13, Financial Instruments—Credit Losses (see Note 1).

Inventories by Major Category
December 31,
20202019
Materials and supplies$260 $278 
Fuel stock236 172 
Natural gas in storage19 19 
Total inventories$515 $469 

Investments
December 31,
20202019
Nuclear plant decommissioning trust$1,674 $1,451 
Assets related to employee benefit plans (Note 17)41 37 
Land44 49 
Total investments$1,759 $1,537 

Investment in Unconsolidated Subsidiary

On the Merger Date, we assumed Dynegy's 50% interest in NELP, a joint venture with NextEra Energy, Inc., which indirectly owned the Bellingham NEA facility and the Sayreville facility. At December 31, 2019, our investment in NELP totaled $123 million.

In December 2019, Dynegy Northeast Generation GP, Inc. and Dynegy Northeast Associates LP, Inc., indirect subsidiaries of Vistra, entered into a transaction agreement with NELP and certain indirect subsidiaries of NextEra Energy, Inc. wherein the indirect subsidiaries of Vistra redeemed their ownership interest in NELP in exchange for 100% ownership interest in NJEA, the company which owns the Sayreville facility. The NELP Transaction was approved by FERC in February 2020, and the NELP Transaction closed on March 2, 2020. As a result of the NELP Transaction, Vistra indirectly owns 100% of the Sayreville facility and no longer has any ownership interest in the Bellingham NEA facility. A loss of $29 million was recognized in connection with the NELP Transaction, reflecting the difference between our derecognized investment in NELP and the value of our acquired 100% interest in NJEA, which was measured in accordance with ASC 805. The loss is reported in our consolidated statements of operations in other deductions.
Equity earnings related to our investment in NELP totaled $3 million, $14 million and $17 million for the years ended December 31, 2020, 2019 and 2018, respectively, recorded in equity in earnings of unconsolidated investment in our consolidated statements of operations. We received distributions totaling $3 million, $22 million and $17 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Nuclear Decommissioning Trust

Investments in a trust that will be used to fund the costs to decommission the Comanche Peak nuclear generation plant are carried at fair value. Decommissioning costs are being recovered from Oncor customers as a delivery fee surcharge over the life of the plant and deposited by Vistra (and prior to the Effective Date, a subsidiary of TCEH) in the trust fund. Income and expense, including gains and losses associated with the trust fund assets and the decommissioning liability, are offset by a corresponding change in a regulatory asset/liability (currently a regulatory liability reported in other noncurrent liabilities and deferred credits) that will ultimately be settled through changes in Oncor's delivery fees rates. If funds recovered from Oncor's customers held in the trust fund are determined to be inadequate to decommission the Comanche Peak nuclear generation plant, Oncor would be required to collect all additional amounts from its customers, with no obligation from Vistra, provided that Vistra complied with PUCT rules and regulations regarding decommissioning trusts. A summary of the fair market value of investments in the fund follows:
Year Ended December 31,
20202019
Debt securities (a)$618 $521 
Equity securities (b)1,056 930 
Total$1,674 $1,451 
____________
(a)The investment objective for debt securities is to invest in a diversified tax efficient portfolio with an overall portfolio rating of AA or above as graded by S&P or Aa2 by Moody's. The debt securities are heavily weighted with government and municipal bonds and investment grade corporate bonds. The debt securities had an average coupon rate of 2.91% and 3.42% at December 31, 2020 and 2019, respectively, and an average maturity of 10 years and 9 years at December 31, 2020 and 2019, respectively.
(b)The investment objective for equity securities is to invest tax efficiently and to match the performance of the S&P 500 Index for U.S. equity investments and the MSCI EAFE Index for non-U.S. equity investments.

Debt securities held at December 31, 2020 mature as follows: $193 million in one to five years, $185 million in five to 10 years and $240 million after 10 years.

The following table summarizes proceeds from sales of securities and investments in new securities.
Year Ended December 31,
202020192018
Proceeds from sales of securities$433 $431 $252 
Investments in securities$(455)$(453)$(274)
Property, Plant and Equipment
December 31,
20202019
Power generation and structures$15,222 $15,205 
Land617 622 
Office and other equipment173 164 
Total16,012 15,991 
Less accumulated depreciation(3,614)(2,553)
Net of accumulated depreciation12,398 13,438 
Finance lease right-of-use assets (net of accumulated depreciation)182 59 
Nuclear fuel (net of accumulated amortization of $91 million and $216 million)
207 197 
Construction work in progress712 220 
Property, plant and equipment — net$13,499 $13,914 

Depreciation expenses totaled $1.377 billion, $1.300 billion and $1.024 billion for the years ended December 31, 2020, 2019 and 2018, respectively.

Our property, plant and equipment consist of our power generation assets, related mining assets, information system hardware, capitalized corporate office lease space and other leasehold improvements. The estimated remaining useful lives range from 1 to 33 years for our property, plant and equipment.
Asset Retirement and Mining Reclamation Obligations (ARO)

These liabilities primarily relate to nuclear generation plant decommissioning, land reclamation related to lignite mining, remediation or closure of coal ash basins, and generation plant disposal costs. There is no earnings impact with respect to changes in the nuclear plant decommissioning liability, as all costs are recoverable through the regulatory process as part of delivery fees charged by Oncor. We have also identified conditional AROs for asbestos removal and disposal, which are specific to certain generation assets. However, because the period of remediation is indeterminable no removal liabilities have been recognized.

At December 31, 2020, the carrying value of our ARO related to our nuclear generation plant decommissioning totaled $1.585 billion, which is lower than the fair value of the assets contained in the nuclear decommissioning trust. Since the costs to ultimately decommission that plant are recoverable through the regulatory rate making process as part of Oncor's delivery fees, a corresponding regulatory liability has been recorded to our consolidated balance sheet of $89 million in other noncurrent liabilities and deferred credits.

The following table summarizes the changes to these obligations, reported as AROs (current and noncurrent liabilities) in our consolidated balance sheets, for the years ended December 31, 2020, 2019 and 2018:
Nuclear Plant DecommissioningMining Land ReclamationCoal Ash and OtherTotal
Liability at December 31, 2017$1,233 $438 $265 $1,936 
Additions:
Accretion43 22 28 93 
Adjustment for change in estimates— 56 (89)(33)
Obligations assumed in the Merger— 475 477 
Reductions:
Payments— (76)(24)(100)
Liability at December 31, 20181,276 442 655 2,373 
Additions:
Accretion44 22 31 97 
Adjustment for change in estimates— 16 (1)15 
Adjustment for obligations assumed through acquisitions— — (3)(3)
Reductions:
Payments— (70)(39)(109)
Liability transfers (a)— — (135)(135)
Liability at December 31, 20191,320 410 508 2,238 
Additions:
Accretion46 20 23 89 
Adjustment for change in estimates (b)219 (6)25 238 
Reductions:
Payments— (65)(49)(114)
Liability transfers (a)— — (15)(15)
Liability at December 31, 20201,585 359 492 2,436 
Less amounts due currently— (92)(11)(103)
Noncurrent liability at December 31, 2020$1,585 $267 $481 $2,333 
____________
(a)Represents ARO transferred to a third-party for remediation. Any remaining unpaid third-party obligation has been reclassified to other current liabilities and other noncurrent liabilities and deferred credits in our consolidated balance sheets.
(b)The adjustment for nuclear plant decommissioning resulted from a new cost estimate completed in 2020. Under applicable accounting standards, the liability is remeasured when significant changes in the amount or timing of cash flows occur, and the PUCT requires a new cost estimate at least every five years. The increase in the liability was driven by changes in assumptions including increased costs for labor, equipment and services and a delay in timing of when the U.S. Department of Energy is estimated to begin accepting spent fuel offsite.
Other Noncurrent Liabilities and Deferred Credits

The balance of other noncurrent liabilities and deferred credits consists of the following:
December 31,
20202019
Retirement and other employee benefits (Note 17)$312 $295 
Identifiable intangible liabilities (Note 6)289 286 
Regulatory liability89 131 
Finance lease liabilities206 78 
Uncertain tax positions, including accrued interest12 10 
Liability for third-party remediation31 41 
Environmental allowances— 52 
Accrued severance costs54 12 
Other accrued expenses138 84 
Total other noncurrent liabilities and deferred credits$1,131 $989 

Fair Value of Debt
December 31, 2020December 31, 2019
Long-term debt (see Note 11):Fair Value HierarchyCarrying AmountFair
Value
Carrying AmountFair
Value
Long-term debt under the Vistra Operations Credit FacilitiesLevel 2$2,579 $2,565 $2,715 $2,717 
Vistra Operations Senior NotesLevel 26,634 7,204 6,620 6,926 
Vistra Senior NotesLevel 2— — 774 772 
Forward Capacity AgreementsLevel 345 45 155 155 
Equipment Financing AgreementsLevel 359 59 87 87 
Building FinancingLevel 210 10 16 16 
Other debtLevel 312 12 

We determine fair value in accordance with accounting standards as discussed in Note 15. We obtain security pricing from an independent party who uses broker quotes and third-party pricing services to determine fair values. Where relevant, these prices are validated through subscription services, such as Bloomberg.

Supplemental Cash Flow Information

The following table reconciles cash, cash equivalents and restricted cash reported in our consolidated statements of cash flows to the amounts reported in our consolidated balance sheets at December 31, 2020 and 2019:
December 31,
20202019
Cash and cash equivalents$406 $300 
Restricted cash included in current assets19 147 
Restricted cash included in noncurrent assets19 28 
Total cash, cash equivalents and restricted cash$444 $475 
The following table summarizes our supplemental cash flow information for the years ended December 31, 2020, 2019 and 2018, respectively.
Year Ended December 31,
202020192018
Cash payments related to:
Interest paid$503 $525 $651 
Capitalized interest(21)(12)(12)
Interest paid (net of capitalized interest)$482 $513 $639 
Income taxes paid / (refunds received) (a)$(140)$(76)$67 
Noncash investing and financing activities:
Accrued property, plant and equipment additions (b)$19 $67 $84 
Disposition of investment in NELP$123 $— $— 
Acquisition of investment in NJEA$90 $— $— 
Shares issued for tangible equity unit contracts (Note 14)$— $446 $— 
Land transferred with liability transfers$— $16 $— 
Vistra common stock issued in the Merger (Notes 2 and 14)$— $— $2,245 
____________
(a)For the years ended December 31, 2020, 2019 and 2018, we paid federal income taxes of zero, zero and $45 million, respectively, paid state income taxes of $40 million, $42 million and $27 million, respectively, received federal tax refunds of $170 million, $115 million and zero, respectively, and received state tax refunds of $10 million, $3 million and $5 million, respectively.
(b)Represents property, plant and equipment accruals during the period for which cash has not been paid as of the end of the period.
v3.20.4
Schedule I - Condensed Financial Information of Registrant
12 Months Ended
Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]  
Schedule I - Condensed Financial Information of Registrant SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT
VISTRA CORP. (PARENT)
SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT
CONDENSED STATEMENTS OF OPERATIONS
(Millions of Dollars)
Year Ended December 31,
202020192018
Depreciation and amortization$(15)$(7)$— 
Selling, general and administrative expenses(72)(62)(266)
Operating loss(87)(69)(266)
Other income12 
Interest expense and related charges(7)(88)(257)
Impacts of Tax Receivable Agreement(37)(79)
Loss before income tax benefit(84)(182)(593)
Income tax benefit25 42 282 
Equity in earnings of subsidiaries, net of tax695 1,068 257 
Net income (loss)$636 $928 $(54)

See Notes to the Condensed Financial Statements.

VISTRA CORP. (PARENT)
SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT
CONDENSED STATEMENTS OF CASH FLOWS
(Millions of Dollars)
Year Ended December 31,
202020192018
Cash flows — operating activities:
Cash used in operating activities$(86)$(58)$(125)
Cash flows — investing activities:
Capital expenditures(15)(36)(24)
Dividend received from subsidiaries1,105 3,890 4,668 
Other, net— — (1)
Cash provided by investing activities1,090 3,854 4,643 
Cash flows — financing activities:
Repayments/repurchases of debt(747)(2,903)(4,543)
Debt tender offer and other debt financing fees(17)(123)(179)
Stock repurchases— (656)(763)
Dividends paid to stockholders(266)(243)— 
Other, net— — 12 
Cash used in financing activities(1,030)(3,925)(5,473)
Net change in cash, cash equivalents and restricted cash(26)(129)(955)
Cash, cash equivalents and restricted cash — beginning balance99 228 1,183 
Cash, cash equivalents and restricted cash — ending balance$73 $99 $228 
See Notes to the Condensed Financial Statements.

VISTRA CORP. (PARENT)
SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT
CONDENSED BALANCE SHEETS
(Millions of Dollars)
December 31,
20202019
ASSETS
Cash and cash equivalents$73 $56 
Restricted cash— 43 
Trade accounts receivable — net
Prepaid expense and other current assets100 
Total current assets85 204 
Investment in affiliated companies8,005 8,364 
Property, plant and equipment — net
Identifiable intangible assets — net47 49 
Accumulated deferred income taxes783 729 
Other noncurrent assets67 
Total assets$8,925 $9,417 
LIABILITIES AND EQUITY
Long-term debt due currently$— $87 
Trade accounts payable
Accounts payable —affiliates74 145 
Accrued taxes14 
Accrued interest— 11 
Other current liabilities46 
Total current liabilities94 291 
Long-term debt, less amounts due currently— 689 
Tax Receivable Agreement obligations447 455 
Other noncurrent liabilities and deferred debits23 22 
Total liabilities564 1,457 
Total stockholders' equity8,361 7,960 
Total liabilities and equity$8,925 $9,417 

See Notes to the Condensed Financial Statements.

NOTES TO CONDENSED FINANCIAL STATEMENTS

1.BASIS OF PRESENTATION

The accompanying unconsolidated condensed balance sheets, statements of net loss and cash flows present results of operations and cash flows of Vistra Corp. (Parent). Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been omitted pursuant to the rules of the SEC. Because the unconsolidated condensed financial statements do not include all of the information and footnotes required by U.S. GAAP, they should be read in conjunction with the financial statements and related notes of Vistra Corp. and Subsidiaries included in the annual report on Form 10-K for the year ended December 31, 2020. Vistra Corp.'s subsidiaries have been accounted for under the equity method. All dollar amounts in the financial statements and tables in the notes are stated in millions of U.S. dollars unless otherwise indicated.

Vistra Corp. (Parent) files a consolidated U.S. federal income tax return. Consolidated tax expenses or benefits and deferred tax assets or liabilities have been allocated to the respective subsidiaries in accordance with the accounting rules that apply to separate financial statements of subsidiaries.
2.RESTRICTIONS ON SUBSIDIARIES

The Credit Facilities Agreement generally restricts the ability of Vistra Operations to make distributions to any direct or indirect parent unless such distributions are expressly permitted thereunder. As of December 31, 2020, Vistra Operations can distribute approximately $6.7 billion to Vistra Corp. (Parent) under the Credit Facilities Agreement without the consent of any party. The amount that can be distributed by Vistra Operations to Parent was partially reduced by distributions made by Vistra Operations to Vistra Corp. (Parent) of approximately $1.1 billion, $3.9 billion and $4.7 billion during the years ended December 31, 2020, 2019 and 2018, respectively. Additionally, Vistra Operations may make distributions to Vistra Corp. (Parent) in amounts sufficient for Vistra Corp. (Parent) to make any payments required under the TRA or the Tax Matters Agreement or, to the extent arising out of Vistra Corp. (Parent)'s ownership or operation of Vistra Operations, to pay any taxes or general operating or corporate overhead expenses. As of December 31, 2020, the maximum amount of restricted net assets of Vistra Operations that may not be distributed to Vistra Corp. (Parent) totaled approximately $1.2 billion.

3.GUARANTEES

Vistra Corp. (Parent) has entered into contracts that contain guarantees to unaffiliated parties that could require performance or payment under certain conditions. As of December 31, 2020, there are no material outstanding claims related to guarantee obligations of Vistra Corp. (Parent), and Vistra Corp. (Parent) does not anticipate it will be required to make any material payments under these guarantees in the near term.

4.DIVIDEND RESTRICTIONS

Under applicable law, Vistra Corp. (Parent) is prohibited from paying any dividend to the extent that immediately following payment of such dividend there would be no statutory surplus or Vistra Corp. (Parent) would be insolvent.

Vistra Corp. (Parent) received $1.105 billion, $3.890 billion and $4.668 billion in dividends from its consolidated subsidiaries in the years ended December 31, 2020, 2019 and 2018, respectively.
v3.20.4
Business And Significant Accounting Policies (Policies)
12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]  
Basis of Presentation
Basis of Presentation

The consolidated financial statements have been prepared in accordance with U.S. GAAP and on the same basis as the audited financial statements included in our 2019 Form 10-K. All intercompany items and transactions have been eliminated in consolidation. All dollar amounts in the financial statements and tables in the notes are stated in millions of U.S. dollars unless otherwise indicated.
Use of Estimates
Use of Estimates

Preparation of financial statements requires estimates and assumptions about future events that affect the reporting of assets and liabilities at the balance sheet dates and the reported amounts of revenue and expense, including fair value measurements, estimates of expected obligations, judgments related to the potential timing of events and other estimates. In the event estimates and/or assumptions prove to be different from actual amounts, adjustments are made in subsequent periods to reflect more current information.
Derivative Instruments and Mark-to-Market Accounting
Derivative Instruments and Mark-to-Market Accounting

We enter into contracts for the purchase and sale of electricity, natural gas, coal, uranium and other commodities utilizing instruments such as options, swaps, futures and forwards primarily to manage commodity price and interest rate risks. If the instrument meets the definition of a derivative under accounting standards related to derivative instruments and hedging activities, changes in the fair value of the derivative are recognized in net income as unrealized gains and losses. This recognition is referred to as mark-to-market accounting. The fair values of our unsettled derivative instruments under mark-to-market accounting are reported in the consolidated balance sheets as commodity and other derivative contractual assets or liabilities. We report derivative assets and liabilities in the consolidated balance sheets without taking into consideration netting arrangements we have with counterparties. Margin deposits that contractually offset these assets and liabilities are reported separately in the consolidated balance sheets, except for certain margin amounts related to changes in fair value on CME transactions that are legally characterized as settlement of derivative contracts rather than collateral. When derivative instruments are settled and realized gains and losses are recorded, the previously recorded unrealized gains and losses and derivative assets and liabilities are reversed. See Notes 15 and 16 for additional information regarding fair value measurement and commodity and other derivative contractual assets and liabilities. A commodity-related derivative contract may be designated as a normal purchase or sale if the commodity is to be physically received or delivered for use or sale in the normal course of business. If designated as normal, the derivative contract is accounted for under the accrual method of accounting (not marked-to-market) with no balance sheet or income statement recognition of the contract until settlement.

Because derivative instruments are frequently used as economic hedges, accounting standards related to derivative instruments and hedging activities allow for hedge accounting, which provides for the designation of such instruments as cash flow or fair value hedges if certain conditions are met. At December 31, 2020 and 2019, there were no derivative positions accounted for as cash flow or fair value hedges.

We report commodity hedging and trading results as revenue, fuel expense or purchased power in the consolidated statements of operations depending on the type of activity. Electricity hedges, financial natural gas hedges and trading activities are primarily reported as revenue. Physical or financial hedges for coal, diesel or uranium, along with physical natural gas trades, are primarily reported as fuel expense. Realized and unrealized gains and losses associated with interest rate swap transactions are reported in the consolidated statements of operations in interest expense.
Revenue Recognition
Revenue Recognition

Revenue is recognized when electricity is delivered to our customers in an amount that we expect to invoice for volumes delivered or services provided. Sales tax is excluded from revenue. Energy sales and services that have been delivered but not billed by period end are estimated. Accrued unbilled revenues are based on estimates of customer usage since the date of the last meter reading provided by the independent system operators or electric distribution companies. Estimated amounts are adjusted when actual usage is known and billed.

We record wholesale generation revenue when volumes are delivered or services are performed for transactions that are not accounted for on a mark-to-market basis. These revenues primarily consist of physical electricity sales to the ISO/RTO, ancillary service revenue for reliability services, capacity revenue for making installed generation and demand response available for system reliability requirements, and certain other electricity sales contracts. See Note 5 for detailed descriptions of revenue from contracts with customers. See Derivative Instruments and Mark-to-Market Accounting for revenue recognition related to derivative contracts.
Advertising Expense
Advertising Expense

We expense advertising costs as incurred and include them within SG&A expenses. Advertising expenses totaled $43 million, $49 million and $46 million for the year ended December 31, 2020, 2019 and 2018, respectively.
Impairment of Long-Lived Assets
Impairment of Long-Lived Assets

We evaluate long-lived assets (including intangible assets with finite lives) for impairment whenever indications of impairment exist. The carrying value of such assets is deemed to be impaired if the projected undiscounted cash flows are less than the carrying value. If there is such impairment, a loss is recognized based on the amount by which the carrying value exceeds the fair value. Fair value is determined primarily by discounted cash flows, supported by available market valuations, if applicable. See Note 21 for details of impairments of long-lived assets recorded in 2020.
Finite-lived intangibles identified as a result of fresh start reporting or purchase accounting are amortized over their estimated useful lives based on the expected realization of economic effects.
Goodwill and Intangible Assets with Indefinite Lives Goodwill and Intangible Assets with Indefinite LivesAs part of fresh start reporting and purchase accounting, reorganization value or the purchase consideration is generally allocated, first, to identifiable tangible assets and liabilities, identifiable intangible assets and liabilities, then any remaining excess reorganization value is allocated to goodwill. We evaluate goodwill and intangible assets with indefinite lives for impairment at least annually, or when indications of impairment exist. We have established October 1 as the date we evaluate goodwill and intangible assets with indefinite lives for impairment.
Nuclear Fuel
Nuclear Fuel

Nuclear fuel is capitalized and reported as a component of our property, plant and equipment in our consolidated balance sheets. Amortization of nuclear fuel is calculated on the units-of-production method and is reported as a component of fuel, purchased power costs and delivery fees in our consolidated statements of operations.
Major Maintenance Costs
Major Maintenance Costs

Major maintenance costs incurred during generation plant outages are deferred and amortized into operating costs over the period between the major maintenance outages for the respective asset. Other routine costs of maintenance activities are charged to expense as incurred and reported as operating costs in our consolidated statements of operations.
Defined Benefit Plans and OPEB Plans
Defined Benefit Pension Plans and OPEB Plans

On the Merger Date, Vistra assumed the pension and OPEB plans that Dynegy had provided to certain of its eligible employees and retirees. The excess of the benefit obligations over the fair value of plan assets was recognized as a liability. See Note 2 for additional information regarding the Merger.

Certain health care and life insurance benefits are offered to eligible employees and their dependents upon the retirement of such employee from the company. Pension benefits are offered to eligible employees under collective bargaining agreements based on either a traditional defined benefit formula or a cash balance formula. Costs of pension and OPEB plans are dependent upon numerous factors, assumptions and estimates.
Stock-Based Compensation Stock-Based CompensationStock-based compensation is accounted for in accordance with ASC 718, Compensation - Stock Compensation. The fair value of our non-qualified stock options is estimated on the date of grant using the Black-Scholes option-pricing model. Forfeitures are recognized as they occur. We recognize compensation expense for graded vesting awards on a straight-line basis over the requisite service period for the entire award.
Sales And Excise Taxes
Sales and Excise Taxes

Sales and excise taxes are accounted for as "pass through" items on the consolidated balance sheets with no effect on the consolidated statements of operations (i.e., the tax is billed to customers and recorded as trade accounts receivable with an offsetting amount recorded as a liability to the taxing jurisdiction in other current liabilities in our consolidated statements of operations).
Franchise And Revenue-Based Taxes
Franchise and Revenue-Based Taxes

Unlike sales and excise taxes, franchise and revenue-based taxes are not "pass through" items. These taxes are imposed on us by state and local taxing authorities, based on revenues or kWh delivered, as a cost of doing business and are recorded as an expense. Rates we charge to customers are intended to recover our costs, including the franchise and revenue-based receipt taxes, but we are not acting as an agent to collect the taxes from customers. We report franchise and revenue-based taxes in SG&A expense in our consolidated statements of operations.
Income Taxes
Income Taxes

On the Merger Date, Vistra and Dynegy effected a merger transaction that for tax purposes was treated as a tax-free reorganization in which Vistra survived as the parent entity. In general, all of Dynegy's tax basis and attributes were transferred to Vistra, including approximately $4.5 billion of utilizable NOLs and refundable alternative minimum tax (AMT) tax credits.

Investment tax credits are accounted for under the deferral method, which resulted in a reduction to the basis of our solar and battery storage facilities of zero, $2 million and $78 million and a corresponding increase in the deferred tax assets in 2020, 2019 and 2018, respectively.

Deferred income taxes are provided for temporary differences between the book and tax basis of assets and liabilities as required under accounting rules. See Note 7.
We report interest and penalties related to uncertain tax positions as current income tax expense.
Tax Receivable Agreement
Tax Receivable Agreement (TRA)

The Company accounts for its obligations under the TRA as a liability in our consolidated balance sheets (see Note 8). The carrying value of the TRA obligation represents the discounted amount of projected payments under the TRA. The projected payments are based on certain assumptions, including but not limited to (a) the federal corporate income tax rate, (b) estimates of our taxable income in the current and future years and (c) additional states that Vistra operates in, including the relevant tax rate and apportionment factor for each state. Our taxable income takes into consideration the current federal tax code and reflects our current estimates of future results of the business.

The carrying value of the obligation is being accreted to the amount of the gross expected obligation using the effective interest method. Changes in the estimated amount of this obligation resulting from changes to either the timing or amount of TRA payments are recognized in the period of change and measured using the discount rate inherent in the initial fair value of the obligation. These changes are included on our consolidated statements of operations under the heading of Impacts of Tax Receivable Agreement.
Accounting for Contingencies Accounting for ContingenciesOur financial results may be affected by judgments and estimates related to loss contingencies. Accruals for loss contingencies are recorded when management determines that it is probable that a liability has been incurred and that such economic loss can be reasonably estimated. Such determinations are subject to interpretations of current facts and circumstances, forecasts of future events and estimates of the financial impacts of such events.
Cash and Cash Equivalents
Cash and Cash Equivalents

For purposes of reporting cash and cash equivalents, temporary cash investments purchased with a remaining maturity of three months or less are considered cash equivalents.
Restricted Cash Restricted CashThe terms of certain agreements require the restriction of cash for specific purposes.
Property, Plant and Equipment
Property, Plant and Equipment

Property, plant and equipment has been recorded at estimated fair values at the time of acquisition for assets acquired or at cost for capital improvements and individual facilities developed (see Notes 2 and 3). Significant improvements or additions to our property, plant and equipment that extend the life of the respective asset are capitalized at cost, while other costs are expensed when incurred. The cost of self-constructed property additions includes materials and both direct and indirect labor, including payroll-related costs. Interest related to qualifying construction projects and qualifying software projects is capitalized in accordance with accounting guidance related to capitalization of interest cost. See Note 21.
Depreciation of our property, plant and equipment (except for nuclear fuel) is calculated on a straight-line basis over the estimated service lives of the properties. Depreciation expense is calculated on an asset-by-asset basis. Estimated depreciable lives are based on management's estimates of the assets' economic useful lives.
Asset Retirement Obligations Asset Retirement Obligations (ARO)A liability is initially recorded at fair value for an asset retirement obligation associated with the legal obligation associated with law, regulatory, contractual or constructive retirement requirements of tangible long-lived assets in the period in which it is incurred if a fair value is reasonably estimable. At initial recognition of an ARO obligation, an offsetting asset is also recorded for the long-lived asset that the liability corresponds with, which is subsequently depreciated over the estimated useful life of the asset. These liabilities primarily relate to our nuclear generation plant decommissioning, land reclamation related to lignite mining and removal of lignite/coal-fueled plant ash treatment facilities. Over time, the liability is accreted for the change in present value and the initial capitalized costs are depreciated over the remaining useful lives of the assets. Generally, changes in estimates related to ARO obligations are recorded as increases or decreases to the liability and related asset as information becomes available. Changes in estimates related to assets that have been retired or for which capitalized costs are not recoverable are recorded as operating costs in the consolidated statements of operations.
Regulatory Asset and Liabilities
Regulatory Asset or Liability

The costs to ultimately decommission the Comanche Peak nuclear power plant are recoverable through the regulatory rate making process as part of Oncor's delivery fees. As a result, the asset retirement obligation and the investments in the decommissioning trust are accounted for as rate regulated operations. Changes in these accounts, including investment income and accretion expense, do not impact net income, but are reported as a change in the corresponding regulatory asset or liability balance that is reflected in our consolidated balance sheets as other noncurrent assets or other noncurrent liabilities and deferred credits.
Inventories InventoriesInventories consist of materials and supplies, fuel stock and natural gas in storage. Materials and supplies inventory is valued at weighted average cost and is expensed or capitalized when used for repairs/maintenance or capital projects, respectively. Fuel stock and natural gas in storage are reported at the lower of cost (calculated on a weighted average basis) or net realizable value. We expect to recover the value of inventory costs in the normal course of business.
Investments
Investments

Investments in a nuclear decommissioning trust fund are carried at current market value in the consolidated balance sheets. Assets related to employee benefit plans represent investments held to satisfy deferred compensation liabilities and are recorded at current market value. See Note 21 for discussion of these and other investments.

Unconsolidated Investments
We use the equity method of accounting for investments in affiliates over which we exercise significant influence. Our share of net income from these affiliates is recorded to equity in earnings of unconsolidated investment in the consolidated statements of operations.
Noncontrolling Interest
Noncontrolling Interest

Noncontrolling interest is comprised of the 20% of Electric Energy, Inc. (EEI) that we do not own. EEI is our consolidated subsidiary that owns a coal facility in Joppa, Illinois. This noncontrolling interest is classified as a component of equity separate from stockholders' equity in the consolidated balance sheets.
Treasury Stock Treasury StockTreasury stock purchases are accounted for under the cost method whereby the entire cost of the acquired stock is recorded as treasury stock, which is presented in our consolidated balance sheets as a reduction to additional paid-in capital.
Leases
Leases

At the inception of a contract we determine if it is or contains a lease, which involves the contract conveying the right to control the use of explicitly or implicitly identified property, plant, or equipment for a period of time in exchange for consideration.

Right-of-use (ROU) assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the commencement date of the underlying lease based on the present value of lease payments over the lease term. We use our secured incremental borrowing rate based on the information available at the lease commencement date to determine the present value of lease payments. Operating leases are included in operating lease ROU assets, operating lease liabilities (current) and operating lease liabilities (noncurrent) on our consolidated balance sheet. Finance leases are included in property, plant and equipment, other current liabilities and other noncurrent liabilities and deferred credits on our consolidated balance sheet. Lease term includes options to extend or terminate the lease when it is reasonably certain that we will exercise the option. We apply the practical expedient permitted by ASC 842 to not separate lease and non-lease components for a majority of our lease asset classes.

Leases with an initial lease term of 12 months or less are not recorded on the balance sheet; we recognize lease expense for these leases on a straight-line basis over the lease term.

We also present lessor sublease income on a net basis against the related lessee lease expense.
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Tables)
12 Months Ended
Dec. 31, 2020
Ambit and Crius Transactions [Member]  
Business Acquisition [Line Items]  
Schedule of recognized identified assets acquired and liabilities assumed
The following table summarizes the allocation of the purchase price to the fair value amounts recognized for the assets acquired and liabilities assumed related to the Ambit Transaction and Crius Transaction, respectively, as of the Ambit Acquisition Date and Crius Acquisition Date, respectively. The Ambit Transaction purchase price was $555 million (including cash acquired and net working capital) and the Crius Transaction purchase price was $400 million. The final purchase price allocations were completed in the second quarter of 2020 for the Crius Transaction and the third quarter of 2020 for the Ambit Transaction.
Ambit Transaction and Crius Transactions Final Purchase Price Allocations
Ambit TransactionCrius Transaction
Final
Purchase Price
Allocation
Measurement Period Adjustments recorded through September 30, 2020Final
Purchase Price
Allocation
Measurement Period Adjustments recorded through June 30, 2020
Cash and cash equivalents$49 $— $26 $— 
Net working capital32 (9)(42)
Accumulated deferred income taxes— — — (36)
Identifiable intangible assets218 (45)317 23 
Goodwill258 44 243 38 
Commodity and other derivative contractual assets23 — 18 — 
Other noncurrent assets13 — 17 (3)
Total assets acquired593 612 (20)
Identifiable intangible liabilities— — (34)
Long-term debt, including amounts due currently— — 140 — 
Commodity and other derivative contractual liabilities28 — 40 — 
Accumulated deferred income taxes— — 14 14 
Other noncurrent liabilities and deferred credits10 16 — 
Total liabilities assumed38 212 (20)
Identifiable net assets acquired$555 $— $400 $— 
Schedule of pro forma financial information
Ambit and Crius Transaction Unaudited Pro Forma Financial Information — The following unaudited consolidated pro forma financial information for the years ended December 31, 2019 and 2018 assumes that the Ambit and Crius Transactions occurred on January 1, 2018 (i.e., represents our results for the years ended December 31, 2019 and 2018 plus the results for either Ambit Transaction or Crius Transaction for the period not owned by us, respectively). The unaudited consolidated pro forma financial information is provided for informational purposes only and is not necessarily indicative of the results of operations that would have occurred had the Ambit Transaction and Crius Transaction been completed on January 1, 2018, nor is the unaudited consolidated pro forma financial information indicative of future results of operations, which may differ materially from the consolidated pro forma financial information presented here.
Ambit TransactionCrius Transaction
Year Ended December 31,Year Ended December 31,
2019201820192018
Revenues$12,931 $10,446 $12,373 $10,379 
Net income (loss) (a)$949 $(95)$876 $(43)
Net income (loss) attributable to Vistra$951 $(93)$878 $(41)
Net income (loss) attributable to Vistra per weighted average share of common stock outstanding — basic$1.92 $(0.18)$1.78 $(0.08)
Net income (loss) attributable to Vistra per weighted average share of common stock outstanding — diluted$1.90 $(0.18)$1.76 $(0.08)
__________
(a)Decrease in pro forma net income compared to consolidated net income is driven by unrealized losses on hedging activities of Crius and amortization of intangible assets.
Dynegy Merger  
Business Acquisition [Line Items]  
Schedule of recognized identified assets acquired and liabilities assumed
The following table summarizes the consideration paid and the final allocation of the purchase price to the fair value amounts recognized for the assets acquired and liabilities assumed related to the Merger as of the Merger Date. Based on the opening price of Vistra common stock on the Merger Date, the purchase price was approximately $2.3 billion. During the three months ended March 31, 2019, the purchase price allocation was completed. During the period from April 9, 2018 through March 31, 2019, we updated the initial purchase price allocation with final valuations by increasing property, plant and equipment by $173 million, decreasing intangible assets by $36 million, increasing goodwill by $175 million, decreasing accounts receivable, inventory, prepaid expenses and other current assets by $10 million, increasing accumulated deferred tax asset by $127 million, decreasing other noncurrent assets by $113 million, increasing trade accounts payable and other current liabilities by $89 million, increasing other noncurrent liabilities by $177 million, increasing asset retirement obligations, including amounts due currently by $56 million as well as other minor adjustments. The valuation revisions were a result of updated inputs used in determining the fair value of the acquired assets and liabilities.

Dynegy shares outstanding as of April 9, 2018 (in millions)144.8 
Exchange Ratio0.652 
Vistra shares issued for Dynegy shares outstanding (in millions)94.4 
Opening price of Vistra common stock on April 9, 2018$19.87 
Purchase price for common stock$1,876 
Fair value of equity component of tangible equity units369 
Fair value of outstanding stock compensation awards attributable to pre-combination service26 
Fair value of outstanding warrants
Total purchase price$2,273 


Dynegy Merger Final Purchase Price Allocation
Cash and cash equivalents$445 
Trade accounts receivables, inventories, prepaid expenses and other current assets853 
Property, plant and equipment10,535 
Accumulated deferred income taxes518 
Identifiable intangible assets351 
Goodwill175 
Other noncurrent assets419 
Total assets acquired13,296 
Trade accounts payable and other current liabilities733 
Commodity and other derivative contractual assets and liabilities, net422 
Asset retirement obligations, including amounts due currently475 
Long-term debt, including amounts due currently8,919 
Other noncurrent liabilities469 
Total liabilities assumed11,018 
Identifiable net assets acquired2,278 
Noncontrolling interest in subsidiary
Total purchase price$2,273 
Schedule of pro forma financial information
Dynegy Merger Unaudited Pro Forma Financial Information — The following unaudited pro forma financial information for the year ended December 31, 2018 assumes that the Merger occurred on January 1, 2018. The unaudited pro forma financial information is provided for informational purposes only and is not necessarily indicative of the results of operations that would have occurred had the Merger been completed on January 1, 2018, nor is the unaudited pro forma financial information indicative of future results of operations, which may differ materially from the pro forma financial information presented here.
Year Ended December 31, 2018
Revenues$10,595 
Net loss$(268)
Net loss attributable to Vistra$(265)
Net loss attributable to Vistra per weighted average share of common stock outstanding — basic$(0.52)
Net loss attributable to Vistra per weighted average share of common stock outstanding — diluted$(0.52)

The unaudited pro forma financial information presented above includes adjustments for incremental depreciation and amortization as a result of the fair value determination of the net assets acquired, interest expense on debt assumed in the Merger, effects of the Merger on tax expense (benefit), changes in the expected impacts of the tax receivable agreement due to the Merger, and other related adjustments.
v3.20.4
Retirement of Generation Facilities (Tables)
12 Months Ended
Dec. 31, 2020
Retirement of Generation Facilities [Abstract]  
Planned Retirements Of Generation Capacity
In December 2020, we announced our intention to retire two natural gas facilities in Texas due to their age, cost profile and small scale, as well as low power prices, limited operational windows and substantial costs to repair, maintain and upgrade the facilities.
NameLocationISO/RTOFuel TypeNet Generation Capacity (MW)Dates Units Retired or
Expected Retirement Date
WhartonBoling, TXERCOTNatural Gas83November 30, 2020
TrinidadTrinidad, TXERCOTNatural Gas244By April 30, 2021
Total327

In September 2020 and December 2020, we announced our intention to retire all of our remaining coal generation facilities in Illinois and Ohio, one coal generation facility in Texas and one natural gas facility in Illinois no later than year-end 2027 due to economic challenges, including incremental expenditures that would be required to comply with the CCR rule and ELG rule (see Note 13), and in furtherance of our efforts to significantly reduce our carbon footprint. Expected plant retirement expenses of $43 million, driven by severance cost, were accrued in the year ended December 31, 2020 in operating costs of our Sunset segment. Operational results for plants with planned retirements are included in our Sunset segment beginning in the quarter when a retirement plan is announced. See Note 21 for discussion of impairments recorded in connection with these announcements.
NameLocationISO/RTOFuel TypeNet Generation Capacity (MW)Expected Retirement Date (a)
BaldwinBaldwin, ILMISOCoal1,185By the end of 2025
Coleto CreekGoliad, TXERCOTCoal650By the end of 2027
JoppaJoppa, ILMISOCoal802By the end of 2025
JoppaJoppa, ILMISONatural Gas221By the end of 2025
KincaidKincaid, ILPJMCoal1,108By the end of 2027
Miami FortNorth Bend, OHPJMCoal1,020By the end of 2027
NewtonNewton, ILMISO/PJMCoal615By the end of 2027
ZimmerMoscow, OHPJMCoal1,300By the end of 2027
Total6,901
____________
(a)Generation facilities may retire earlier than expected dates if economic or other conditions dictate.
Planned And Completed Retirements Of Generation Capacity In September 2019, we announced the settlement of a lawsuit alleging violations of opacity and particulate matter limits at our Edwards facility in Bartonville, Illinois. As part of the settlement, which was approved by the U.S. District Court for the Central District of Illinois in November 2019, we will retire the Edwards facility by the end of 2022 (see Note 13). In August 2019, we announced the planned retirement of four additional power plants in Illinois with a total installed nameplate generation capacity of 2,068 MW. We retired these units due to changes in the Illinois multi-pollutant standard rule (MPS rule) that require us to retire approximately 2,000 MW of generation capacity (see Note 13). In light of the provisions of the Federal Power Act and the FERC regulations thereunder, the affected subsidiaries of Vistra identified the retired units by analyzing the economics of each of our Illinois plants and designating the least economic units for retirement. Expected plant retirement expenses of $47 million, driven by severance costs, were accrued in the year ended December 31, 2019 and were included primarily in operating costs of our Asset Closure segment. In August 2019, we remeasured our pension and OPEB plans resulting in an increase to the benefit obligation liability of $21 million, pretax other comprehensive loss of $18 million and curtailment expense of $3 million recognized as other deductions in our consolidated statements of operations. The following table details the units in Illinois totaling 2,653 MW that have been or will be retired. Operational results for the four retired plants identified below are included in the Asset Closure segment, which is engaged in the decommissioning and reclamation of retired plants and mines. Operational results for the Edwards facility are included in the Sunset segment.
NameLocationISO/RTOFuel TypeNet Generation Capacity (MW)Dates Units Retired or
Expected Retirement Date
CoffeenCoffeen, ILMISOCoal915 November 1, 2019
Duck CreekCanton, ILMISOCoal425 December 15, 2019
HavanaHavana, ILMISOCoal434 November 1, 2019
HennepinHennepin, ILMISOCoal294 November 1, 2019
EdwardsBartonville, ILMISOCoal585 By the end of 2022
Total2,653 
Retirements Of Generation Capacity [Table Text Block]
Two of our non-operated, jointly held power plants acquired in the Merger, for which our proportional generation capacity was 883 MW, were retired in May 2018. These units were retired as previously scheduled. No gain or loss was recorded in conjunction with the retirement of these units, and the operational results of these facilities are included in our Asset Closure segment. The following table details the units retired.
NameLocationISO/RTOFuel TypeNet Generation Capacity (MW)Ownership InterestDate Units Retired
KillenManchester, OhioPJMCoal204 33%May 31, 2018
StuartAberdeen, OhioPJMCoal679 39%May 24, 2018
Total
883 

In January and February 2018, we retired three power plants in Texas with a total installed nameplate generation capacity of 4,167 MW. We decided to retire these units because they were projected to be uneconomic based on then current market conditions and would have faced significant environmental costs associated with operating such units. In the case of the Sandow units, the decision also reflected the execution of a contract termination agreement pursuant to which the Company and Alcoa agreed to an early settlement of a long-standing power and mining agreement. Expected retirement expenses were accrued in the third and fourth quarter of 2017 and, as a result, no retirement expenses were recorded related to these facilities in the year ended December 31, 2018. The operational results of these facilities are included in our Asset Closure segment. The following table details the units retired.
NameLocation (all in the state of Texas)ISO/RTOFuel TypeInstalled Nameplate Generation Capacity (MW)Date Units Retired
MonticelloTitus CountyERCOTLignite/Coal1,880 January 4, 2018
SandowMilam CountyERCOTLignite1,137 January 11, 2018
Big BrownFreestone CountyERCOTLignite/Coal1,150 February 12, 2018
Total
4,167 
v3.20.4
Revenue (Tables)
12 Months Ended
Dec. 31, 2020
Revenue from Contract with Customer [Abstract]  
Disaggregation of Revenue
The following tables disaggregate our revenue by major source:
Year Ended December 31, 2020
RetailTexasEastWestSunsetAsset ClosureEliminationsConsolidated
Revenue from contracts with customers:
Retail energy charge in ERCOT$5,813 $— $— $— $— $— $— $5,813 
Retail energy charge in Northeast/Midwest2,406 — — — — — — 2,406 
Wholesale generation revenue from ISO/RTO— 475 310 124 473 — 1,383 
Capacity revenue from ISO/RTO (a)— — (52)— 164 — — 112 
Revenue from other wholesale contracts— 226 668 54 187 — 1,136 
Total revenue from contracts with customers8,219 701 926 178 824 — 10,850 
Other revenues:
Intangible amortization(5)— — (21)— — (24)
Hedging and other revenues (b)56 416 (108)101 151 — 617 
Affiliate sales— 2,999 1,595 298 — (4,895)— 
Total other revenues51 3,415 1,489 104 428 (4,895)593 
Total revenues$8,270 $4,116 $2,415 $282 $1,252 $$(4,895)$11,443 
____________
(a)Represents net capacity sold (purchased) in each ISO/RTO. The East segment includes net purchases of capacity in the PJM market and the Sunset segment includes net sales of capacity in the PJM market.
(b)Includes $164 million of unrealized net gains from mark-to-market valuations of commodity positions. See Note 20 for unrealized net gains (losses) by segment.


Year Ended December 31, 2019
RetailTexasEastWestSunsetAsset ClosureEliminationsConsolidated
Revenue from contracts with customers:
Retail energy charge in ERCOT$4,983 $— $— $— $— $— $— $4,983 
Retail energy charge in Northeast/Midwest1,818 — — — — — — 1,818 
Wholesale generation revenue from ISO/RTO— 1,477 629 193 751 194 — 3,244 
Capacity revenue from ISO/RTO— — 170 — 197 11 — 378 
Revenue from other wholesale contracts— 264 702 147 — 1,124 
Total revenue from contracts with customers6,801 1,741 1,501 202 1,095 207 — 11,547 
Other revenues:
Intangible amortization(15)— (4)(17)— — (32)
Hedging and other revenues (a)86 (250)37 132 247 42 — 294 
Affiliate sales— 2,345 1,256 — 277 92 (3,970)— 
Total other revenues71 2,095 1,289 136 507 134 (3,970)262 
Total revenues$6,872 $3,836 $2,790 $338 $1,602 $341 $(3,970)$11,809 
____________
(a)Includes $682 million of unrealized net gains from mark-to-market valuations of commodity positions. See Note 20 for unrealized net gains (losses) by segment.
Year Ended December 31, 2018
RetailTexasEastWestSunsetAsset ClosureEliminationsConsolidated
Revenue from contracts with customers:
Retail energy charge in ERCOT$4,426 $— $— $— $— $— $— $4,426 
Retail energy charge in Northeast/Midwest1,123 — — — — — — 1,123 
Wholesale generation revenue from ISO/RTO— 1,049 867 167 825 218 — 3,126 
Capacity revenue from ISO/RTO— — 376 30 258 34 — 698 
Revenue from other wholesale contracts— 214 67 137 — — 424 
Total revenue from contracts with customers5,549 1,263 1,310 203 1,220 252 — 9,797 
Other revenues:
Intangible amortization(26)(1)(9)— (7)— — (43)
Hedging and other revenues (a)74 (387)16 (214)(106)(610)
Affiliate sales— 1,622 578 — 184 225 (2,609)— 
Total other revenues48 1,234 585 (37)119 (2,607)(653)
Total revenues$5,597 $2,497 $1,895 $208 $1,183 $371 $(2,607)$9,144 
____________
(a)Includes $380 million of unrealized net losses from mark-to-market valuations of commodity positions. See Note 20 for unrealized net gains (losses) by segment.
Accounts Receivable, Contracts With Customers
The following table presents trade accounts receivable (net of allowance for uncollectible accounts) relating to both contracts with customers and other activities:
December 31,
20202019
Trade accounts receivable from contracts with customers — net$1,169 $1,246 
Other trade accounts receivable — net110 119 
Total trade accounts receivable — net$1,279 $1,365 
v3.20.4
Goodwill and Identifiable Intangible Assets and Liabilities (Tables)
12 Months Ended
Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of goodwill
The following table provides information regarding our goodwill balance. There have been no impairments of goodwill since Emergence.

Balance at December 31, 2018$2,068 
Measurement period adjustments recorded in connection with the Merger14 
Goodwill recorded in connection with the Crius Transaction257 
Goodwill recorded in connection with the Ambit Transaction214 
Balance at December 31, 20192,553 
Measurement period adjustments recorded in connection with the Crius Transaction(14)
Measurement period adjustments recorded in connection with the Ambit Transaction44 
Balance at December 31, 2020$2,583 
Schedule of identifiable intangible assets reported in balance sheet
Identifiable intangible assets are comprised of the following:
December 31, 2020December 31, 2019
Identifiable Intangible AssetGross
Carrying
Amount
Accumulated
Amortization
NetGross
Carrying
Amount
Accumulated
Amortization
Net
Retail customer relationship$2,082 $1,434 $648 $2,078 $1,151 $927 
Software and other technology-related assets414 186 228 341 125 216 
Retail and wholesale contracts272 204 68 315 182 133 
Contractual service agreements (a)51 50 59 54 
Other identifiable intangible assets (b)96 19 77 40 15 25 
Total identifiable intangible assets subject to amortization$2,915 $1,844 1,071 $2,833 $1,478 1,355 
Retail trade names (not subject to amortization)1,374 1,391 
Mineral interests (not currently subject to amortization)
Total identifiable intangible assets$2,446 $2,748 
____________
(a)At December 31, 2020, amounts related to contractual service agreements that have become liabilities due to amortization of the economic impacts of the intangibles have been removed from both the gross carrying amount and accumulated amortization.
(b)Includes mining development costs and environmental allowances (emissions allowances and renewable energy certificates).
Schedule of identifiable intangible liabilities reported in balance sheet
Identifiable intangible liabilities are comprised of the following:
Year Ended December 31,
Identifiable Intangible Liability20202019
Contractual service agreements
$129 $110 
Purchase and sale of power and capacity
87 100 
Fuel and transportation purchase contracts73 76 
Total identifiable intangible liabilities$289 $286 
Schedule of amortization expense related to intangible assets and liabilities (including income statement line item) related to finite-lived identifiable intangible assets and liabilities (including the classification in the consolidated statements of operations) consisted of:
Identifiable Intangible Assets and LiabilitiesConsolidated Statements of OperationsRemaining useful lives of identifiable intangible assets at December 31,
2020 (weighted average in years)
Year Ended December 31,
202020192018
Retail customer relationshipDepreciation and amortization3$283 $275 $304 
Software and other technology-related assetsDepreciation and amortization473 61 62 
Retail and wholesale contracts/purchase and sale/fuel and transportation contractsOperating revenues/fuel, purchased power costs and delivery fees317 23 43 
Other identifiable intangible assetsOperating revenues/fuel, purchased power costs and delivery fees/depreciation and amortization5223 148 58 
Total intangible asset expense (a)$596 $507 $467 
____________
(a)Amounts recorded in depreciation and amortization totaled $360 million, $340 million and $370 million for the years ended December 31, 2020, 2019 and 2018 respectively. Amounts exclude contractual services agreements. Amounts include all expenses associated with environmental allowances including expenses accrued to comply with emissions allowance programs and renewable portfolio standards which are presented in fuel, purchased power costs and delivery fees on our consolidated statements of operations. Emissions allowance obligations are accrued as associated electricity is generated and renewable energy certificate obligations are accrued as retail electricity delivery occurs.
Schedule of estimated amortization expense of identifiable intangible assets
As of December 31, 2020, the estimated aggregate amortization expense of identifiable intangible assets and liabilities for each of the next five fiscal years is as shown below.
YearEstimated Amortization Expense
2021$276 
2022$183 
2023$128 
2024$78 
2025$54 
v3.20.4
Income Taxes (Tables)
12 Months Ended
Dec. 31, 2020
Income Tax Disclosure [Abstract]  
Schedule of components of income tax expense (benefit)
The components of our income tax expense (benefit) are as follows:
Year Ended December 31,
202020192018
Current:
U.S. Federal$(5)$(1)$(13)
State41 10 30 
Total current36 17 
Deferred:
U.S. Federal171 260 (8)
State59 21 (54)
Total deferred230 281 (62)
Total$266 $290 $(45)
Schedule of reconciliation of income taxes computed at the U.S. federal statutory rate to income tax expense (benefit) recorded
Reconciliation of income taxes computed at the U.S. federal statutory rate to income tax expense (benefit) recorded:
Year Ended December 31,
202020192018
Income (loss) before income taxes$890 $1,216 $(101)
U.S. federal statutory rate21 %21 %21 %
Income taxes at the U.S. federal statutory rate187 255 (20)
Nondeductible TRA accretion(7)
State tax, net of federal benefit32 48 22 
Federal and State return to provision adjustment13 (17)(12)
Remeasurement of historical Vistra deferred taxes for expanded state footprint— — (54)
Effect of refundable minimum tax credits no longer subject to sequestration— — (15)
Nondeductible compensation— 
Nondeductible transaction costs— 
Equity awards— (4)(3)
Valuation allowance on state NOLs41 13 20 
Lignite depletion(3)(6)— 
Texas gross margin amended return— (3)— 
Other(6)(2)
Income tax expense (benefit)$266 $290 $(45)
Effective tax rate29.9 %23.8 %44.6 %
Schedule of deferred tax assets and liabilities
Deferred income taxes provided for temporary differences based on tax laws in effect at December 31, 2020 and 2019 are as follows:
December 31,
20202019
Noncurrent Deferred Income Tax Assets
Tax credit carryforwards$75 $73 
Loss carryforwards953 921 
Identifiable intangible assets293 214 
Long-term debt19 257 
Employee benefit obligations129 112 
Commodity contracts and interest rate swaps96 108 
Other47 43 
Total deferred tax assets$1,612 $1,728 
Noncurrent Deferred Income Tax Liabilities
Property, plant and equipment632 554 
Total deferred tax liabilities632 554 
Valuation allowance143 110 
Net Deferred Income Tax Asset$837 $1,064 
Schedule of income tax contingencies The following table summarizes the changes to the uncertain tax positions, reported in accumulated deferred income taxes and other current liabilities in the consolidated balance sheets for the years ended December 31, 2020, 2019 and 2018.
Year Ended December 31,
202020192018
Balance at beginning of period, excluding interest and penalties$126 $39 $— 
Additions allocated in the Merger— — 39 
Additions based on tax positions related to prior years— 
Reductions based on tax positions related to prior years(90)— — 
Additions based on tax positions related to the current year— 87 — 
Settlements with taxing authorities— (3)— 
Balance at end of period, excluding interest and penalties$39 $126 $39 
v3.20.4
Tax Receivable Agreement Obligation (Tables)
12 Months Ended
Dec. 31, 2020
Income Tax Disclosure [Abstract]  
Schedule of Tax Receivable Agreement obligation
The following table summarizes the changes to the TRA obligation, reported as other current liabilities and Tax Receivable Agreement obligation in our consolidated balance sheets, for the years ended December 31, 2020, 2019 and 2018.
Year Ended December 31,
202020192018
TRA obligation at the beginning of the period$455 $420 $357 
Accretion expense64 59 65 
Changes in tax assumptions impacting timing of payments (a)(69)(22)14 
Impacts of Tax Receivable Agreement(5)37 79 
Payments— (2)(16)
TRA obligation at the end of the period450 455 420 
Less amounts due currently(3)— — 
Noncurrent TRA obligation at the end of the period$447 $455 $420 
____________
(a)During the year ended December 31, 2020, we recorded a decrease to the carrying value of the TRA obligation totaling $69 million as a result of adjustments to forecasted taxable income, including the impacts of the CARES Act, changes to Section 163(j) percentage limitation amount, the impacts from the issuance of the final Section 163(j) regulations and the anticipated tax benefits from renewable development projects. During the year ended December 31, 2019, we recorded a decrease to the carrying value of the TRA obligation totaling approximately $22 million as a result of adjustments to the timing of forecasted taxable income and state apportionment due to the expansion of Vistra's state income tax profile, including the Dynegy, Crius and Ambit acquisitions. During the year ended December 31, 2018, we recorded an increase to the carrying value of the TRA obligation totaling $14 million related to changes in the timing of estimated payments resulting changes in the timing of estimated payments and new multistate tax impacts resulting from the Merger.
v3.20.4
Earnings Per Share (Tables)
12 Months Ended
Dec. 31, 2020
Earnings Per Share [Abstract]  
Schedule of earnings per share, basic and diluted [Table Text Block]
Basic earnings per share available to common stockholders are based on the weighted average number of common shares outstanding during the period. Diluted earnings per share is calculated using the treasury stock method and includes the effect of all potential issuances of common shares under stock-based incentive compensation arrangements.
Year Ended December 31,
202020192018
Net income (loss) attributable to common stock — basic$636 $928 $(54)
Weighted average shares of common stock outstanding — basic488,668,263 494,146,268 504,954,371 
Net income (loss) per weighted average share of common stock outstanding — basic$1.30 $1.88 $(0.11)
Dilutive securities: Stock-based incentive compensation plan2,422,205 5,789,223 — 
Weighted average shares of common stock outstanding — diluted491,090,468 499,935,490 504,954,371 
Net income (loss) per weighted average share of common stock outstanding — diluted$1.30 $1.86 $(0.11)
v3.20.4
Long-Term Debt (Tables)
12 Months Ended
Dec. 31, 2020
Debt Disclosure [Abstract]  
Schedule of long-term debt instruments
Amounts in the table below represent the categories of long-term debt obligations incurred by the Company.
December 31,
20202019
Vistra Operations Credit Facilities$2,572 $2,700 
Vistra Operations Senior Secured Notes:
3.550% Senior Secured Notes, due July 15, 2024
1,500 1,500 
3.700% Senior Secured Notes, due January 30, 2027
800 800 
4.300% Senior Secured Notes, due July 15, 2029
800 800 
Total Vistra Operations Senior Secured Notes3,100 3,100 
Vistra Operations Senior Unsecured Notes:
5.500% Senior Unsecured Notes, due September 1, 2026
1,000 1,000 
5.625% Senior Unsecured Notes, due February 15, 2027
1,300 1,300 
5.000% Senior Unsecured Notes, due July 31, 2027
1,300 1,300 
Total Vistra Operations Senior Unsecured Notes3,600 3,600 
Vistra Senior Unsecured Notes:
5.875% Senior Unsecured Notes, due June 1, 2023
— 500 
8.000% Senior Unsecured Notes, due January 15, 2025
— 81 
8.125% Senior Unsecured Notes, due January 30, 2026
— 166 
Total Vistra Senior Unsecured Notes— 747 
Other:
Forward Capacity Agreements45 161 
Equipment Financing Agreements68 99 
8.82% Building Financing due semiannually through February 11, 2022 (a)
10 15 
Other12 
Total other long-term debt126 287 
Unamortized debt premiums, discounts and issuance costs (b)(68)(55)
Total long-term debt including amounts due currently9,330 10,379 
Less amounts due currently(95)(277)
Total long-term debt less amounts due currently$9,235 $10,102 
____________
(a)Obligation related to a corporate office space finance lease. This obligation will be funded by amounts held in an escrow account that is reflected in other noncurrent assets in our consolidated balance sheets.
(b)Includes impact of recording debt assumed in the Merger at fair value.
Schedule of line of credit facilities
The Vistra Operations Credit Facilities and related available capacity at December 31, 2020 are presented below.
December 31, 2020
Vistra Operations Credit FacilitiesMaturity DateFacility
Limit
Cash
Borrowings
Letters of Credit OutstandingAvailable
Capacity
Revolving Credit Facility (a)June 14, 2023$2,725 $— $737 $1,988 
Term Loan B-3 Facility (b)December 31, 20252,572 2,572 — 
Total Vistra Operations Credit Facilities$5,297 $2,572 $737 $1,988 
___________
(a)Revolving Credit Facility to be used for general corporate purposes. The Facility includes a $2.35 billion letter of credit sub-facility. Letters of credit outstanding reduce our available capacity. Cash borrowings under the Revolving Credit Facility are reported in short-term borrowings in our consolidated balance sheets.
(b)Beginning in 2020, cash borrowings under the Term Loan B-3 Facility are subject to a required scheduled quarterly payment in annual amount equal to 1.00% of the original principal amount with the balance paid at maturity. Amounts paid cannot be reborrowed.
Schedule of interest rate derivatives
Interest Rate Swaps — Vistra employs interest rate swaps to hedge our exposure to variable rate debt. As of December 31, 2020, Vistra has entered into the following series of interest rate swap transactions.
Notional AmountExpiration DateRate Range
Swapped to fixed$3,000July 20233.67 %-3.91%
Swapped to variable$700July 20233.20 %-3.23%
Swapped to fixed (a)$720February 20243.71 %-3.72%
Swapped to variable$720February 20243.20 %-3.20%
Swapped to fixed (b)$3,000July 20264.72 %-4.79%
Swapped to variable (b)$700July 20263.28 %-3.33%
____________
(a)In June 2018, we completed the novation of $1.959 billion of Vistra (legacy Dynegy) interest rate swaps to Vistra Operations, of which $398 million expired and $841 million were terminated in June 2019.
(b)Effective from July 2023 through July 2026.
Schedule of debt securities issued, secured
In 2019, Vistra Operations issued and sold $3.1 billion aggregate principal amount of senior secured notes (June 2019 Senior Secured Notes and the November 2019 Senior Secured Notes) in offerings (the June 2019 Senior Secured Notes Offering and the November 2019 Senior Secured Notes Offering) to eligible purchasers under Rule 144A and Regulation S under the Securities Act consisting of the following:
Senior Secured NotesMaturity YearInterest Terms
(Due Semiannually in Arrears)
June 2019
Senior Secured Notes Offering (a)
November 2019 Senior Secured Notes Offering (b)
3.550% Senior Secured Notes
2024January 15 and July 15$1,200 $300 
3.700% Senior Secured Notes
2027January 30 and July 30— 800 
4.300% Senior Secured Notes
2029January 15 and July 15800 — 
Total senior secured notes$2,000 $1,100 
Net proceeds$1,976 $1,099 
Debt issuance and other fees (c)$20 $10 
___________
(a)The June 2019 Senior Secured Notes were sold pursuant to a purchase agreement by and among Vistra Operations, certain direct and indirect subsidiaries of Vistra Operations and Citigroup Global Markets Inc., as representative of the several initial purchasers. Net proceeds, together with cash on hand, were used to prepay certain amounts outstanding and accrued interest (together with fees and expenses) under the Term Loan B Facility.
(b)The November 2019 Senior Secured Notes were sold pursuant to a purchase agreement by and among Vistra Operations, certain direct and indirect subsidiaries of Vistra Operations and J.P. Morgan Securities LLC., as representative of the several initial purchasers. Net proceeds, together with borrowings under the Term Loan B-3 Facility and cash on hand, were used to repay the entire amount outstanding and accrued interest (together with fees and expenses) under the Term Loan B-1 Facility.
(c)Capitalized as a reduction in the carrying amount of the debt.
Schedule of debt securities issued, unsecured
In 2018 and 2019, Vistra Operations issued and sold $3.6 billion aggregate principal amount of senior unsecured notes in offerings (the August 2018 Senior Unsecured Notes Offering, the February 2019 Senior Unsecured Notes Offering and the June 2019 Senior Unsecured Notes Offerings) to eligible purchasers under Rule 144A and Regulation S under the Securities Act consisting of the following:
Senior Unsecured NotesMaturity YearInterest Terms
(Due Semiannually in Arrears)
August 2018 Senior Unsecured Notes Offering (a)February 2019 Senior Unsecured Notes Offering (b)June 2019
Senior Unsecured Notes Offering (c)
5.500% Senior Unsecured Notes
2026March 1 and September 1$1,000 $— $— 
5.625% Senior Unsecured Notes
2027February 15 and August 15— 1,300 — 
5.000% Senior Unsecured Notes
2027January 31 and July 31— — 1,300 
Total$1,000 $1,300 $1,300 
Net Proceeds$990 $1,287 $1,287 
Debt issuance and other fees (d)$12 $16 $13 
___________
(a)The 5.500% senior unsecured notes due 2026 (the August 2018 Senior Unsecured Notes) were sold pursuant to a purchase agreement by and among Vistra Operations, the Guarantor Subsidiaries and Citigroup Global Markets Inc., as representative of the several initial purchasers. Net proceeds, together with cash on hand and cash received from the funding of the Receivables Facility (see Note 10), were used to pay the purchase price and accrued interest (together with fees and expenses) required in connection with the 2018 Tender Offers (defined below).
(b)The 5.625% senior unsecured notes due 2027 (the February 2019 Senior Unsecured Notes) were sold pursuant to a purchase agreement by and among Vistra Operations, the Guarantor Subsidiaries and J.P. Morgan Securities LLC., as representative of the several initial purchasers. Net proceeds, together with cash on hand, were used to pay the purchase price and accrued interest (together with fees and expenses) required in connection with (i) the February 2019 Tender Offer, (defined below) and (ii) the redemption of approximately $35 million aggregate principal amount of our 7.375% senior unsecured notes due 2022 (7.375% senior notes) and approximately $25 million aggregate principal amount of our outstanding 8.034% senior unsecured notes due 2024 (8.034% senior notes).
(c)The 5.000% senior unsecured notes due 2027 (the June 2019 Senior Unsecured Notes) were sold pursuant to a purchase agreement by and among Vistra Operations, the Guarantor Subsidiaries and Goldman Sachs & Co. LLC, as representative of the several initial purchasers. Net proceeds, together with cash on hand, were used to pay the purchase price and accrued interest (together with fees and expenses) required in connection with (i) the June 2019 Tender Offer (defined below) and (ii) the redemption of approximately $306 million of our outstanding 7.375% senior notes and approximately $87 million of our 7.625% senior unsecured notes due 2024 (7.625% senior notes) in July 2019. We recorded an extinguishment gain of $2 million on the redemptions in the year ended December 31, 2019.
(d)Capitalized as a reduction in the carrying amount of the debt.
Schedule of debt securities repurchased, unsecured
Following the redemption, repurchase and tender offer transactions below, Vistra had no outstanding senior notes at the Parent level.
Vistra Senior Unsecured NotesMaturity Year2018 Redemptions/Repurchases (a)August
2018 Tender Offer (b)
February 2019 Tender Offer (c)June
2019 Tender Offer (d)
2019 Redemptions (e)2020 Redemptions (f)
6.750%Senior Unsecured Notes
2019$850 $— $— $— $— $— 
7.375% Senior Unsecured Notes
202243 — 1,193 173 341 — 
5.875% Senior Unsecured Notes
2023— — — — — 500 
7.625% Senior Unsecured Notes
202477 26 — 672 475 — 
8.034% Senior Unsecured Notes
2024— 163 — — 25 — 
8.000% Senior Unsecured Notes
2025— 669 — — — 81 
8.125%Senior Unsecured Notes
2026— 684 — — — 166 
Total$970 $1,542 $1,193 $845 $841 $747 
Extinguishment gain/(loss)$— $(27)$$$11 $11 
____________
(a)In May 2018, $850 million of outstanding 6.75% senior unsecured notes due 2019 were redeemed at a redemption price of 101.688% of the aggregate principal amount, plus accrued and unpaid interest up to but not including the date of redemption. Fees and expenses related to the redemption totaled $14 million in the year ended December 31, 2018 and were recorded as interest expense and other charges on the consolidated statements of operations. In addition, Vistra repurchased $119 million of Vistra Senior Unsecured Notes under the bond repurchase program described above.
(b)In August 2018, Vistra used the net proceeds from the August 2018 Senior Unsecured Notes Offering, proceeds from the Receivables Facility (see Note 10) and cash on hand to fund cash tender offers (the 2018 Tender Offers) to purchase for cash $1.542 billion aggregate principal amount of Vistra Senior Unsecured Notes.
(c)In February 2019, Vistra used the net proceeds from the February 2019 Senior Unsecured Notes Offering to fund a cash tender offer (the February 2019 Tender Offer) to purchase for cash $1.193 billion aggregate principal amount of 7.375% senior notes.
(d)In June 2019, Vistra used the net proceeds from the June 2019 Notes Offering to fund a cash tender offer (the June 2019 Tender Offer) to purchase for cash $173 million of 7.375% senior notes and $672 million of 7.625% senior notes. In July 2019, Vistra accepted and settled an additional approximately $1 million aggregate principal amount of outstanding 7.625% senior notes that were tendered after the early tender date of the June 2019 Tender Offer.
(e)In November 2019, Vistra redeemed $387 million aggregate principal amount outstanding of 7.625% senior notes at a redemption price equal to 103.8% of the aggregate principal amount thereof, plus accrued and unpaid interest to, but excluding, the date of redemption (the 2019 Redemption). Vistra redeemed $341 million, $87 million and $25 million aggregate principal amount of 7.375% senior notes, 7.625% senior notes and 8.034% senior notes, respectively, using proceeds from the February 2019 Senior Unsecured Notes Offering and the June 2019 Senior Unsecured Notes Offerings discussed above.
(f)In January 2020, June 2020 and July 2020, Vistra redeemed aggregate principal amounts of $81 million of 8.000% senior notes, $500 million of 5.875% senior notes and $166 million of 8.125% senior notes, respectively, at redemption prices of 104%, 100.979% and 104.063%, respectively, of the aggregate principal amounts thereof, plus accrued and unpaid interest to, but excluding, the dates of redemption (the 2020 Redemptions, and together with the 2019 Redemption, the Redemptions)
Schedule of maturities of long-term debt
Long-term debt maturities at December 31, 2020 are as follows:
December 31, 2020
2021$98 
202244 
202340 
20241,540 
20252,470 
Thereafter5,206 
Unamortized premiums, discounts and debt issuance costs(68)
Total long-term debt, including amounts due currently$9,330 
v3.20.4
Leases (Tables)
12 Months Ended
Dec. 31, 2020
Leases [Abstract]  
Schedule of lease cost
Lease Cost

The following table presents costs related to lease activities:
Year Ended December 31,
20202019
Operating lease cost$14 $14 
Finance lease:
Finance lease right-of-use asset amortization
Interest on lease liabilities
Total finance lease cost14 
Variable lease cost (a)29 26 
Short-term lease cost31 19 
Sublease income (b)(8)(8)
Net lease cost$80 $59 
____________
(a)Represents coal stockpile management services, common area maintenance services and rail car payments based on the number of rail cars used.
(b)Represents sublease income related to real estate leases.
Schedule of lease balance sheet information
Balance Sheet Information

The following table presents lease related balance sheet information:
December 31,
20202019
Lease assets:
Operating lease right-of-use assets$45 $44 
Finance lease right-of-use assets (net of accumulated depreciation)182 $59 
Total lease right-of-use assets227 103 
Current lease liabilities:
Operating lease liabilities14 
Finance lease liabilities
Total current lease liabilities16 22 
Noncurrent lease liabilities:
Operating lease liabilities40 41 
Finance lease liabilities206 78 
Total noncurrent lease liabilities246 119 
Total lease liabilities$262 $141 
Schedule of lease cash flow and other information
Cash Flows and Other Information

The following table presents lease related cash flows and other information:
Year Ended December 31,
20202019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases$17 $17 
Operating cash flows from finance leases
Finance cash flows from finance leases10 
Non-cash disclosure upon commencement of new lease:
Right-of-use assets obtained in exchange for new operating lease liabilities14 95 
Right-of-use assets obtained in exchange for new finance lease liabilities108 13 
Non-cash disclosure upon modification of existing lease:
Modification of operating lease right-of-use assets(1)(41)
Modification of finance lease right-of-use assets23 50 
Schedule of weighted average remaining lease terms and discount rates
Weighted Average Remaining Lease Term

The following table presents weighted average remaining lease term information:
December 31,
20202019
Weighted average remaining lease term:
Operating lease12.3 years7.5 years
Finance lease24.2 years16.2 years
Weighted average discount rate:
Operating lease5.80%5.34 %
Finance lease4.92%5.84 %
Schedule of maturity of operating lease liabilities
Maturity of Lease Liabilities

The following table presents maturity of lease liabilities:
Operating LeaseFinance LeaseTotal Lease
2021$11 $14 $25 
202220 28 
202319 28 
202419 24 
202519 22 
Thereafter41 385 426 
Total lease payments77 476 553 
Less: Interest(29)(262)(291)
Present value of lease liabilities$48 $214 $262 
Schedule of maturity of finance lease liabilities
Maturity of Lease Liabilities

The following table presents maturity of lease liabilities:
Operating LeaseFinance LeaseTotal Lease
2021$11 $14 $25 
202220 28 
202319 28 
202419 24 
202519 22 
Thereafter41 385 426 
Total lease payments77 476 553 
Less: Interest(29)(262)(291)
Present value of lease liabilities$48 $214 $262 
v3.20.4
Commitments and Contingencies (Tables)
12 Months Ended
Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]  
Schedule of contractual commitments under energy-related contracts, leases and other agreements [Table Text Block]
At December 31, 2020, we had contractual commitments under long-term service and maintenance contracts, energy-related contracts, leases and other agreements as follows.
Long-Term Service and Maintenance ContractsCoal purchase and
transportation agreements
Pipeline transportation and storage reservation feesNuclear
Fuel Contracts
Other
Contracts
2021$165 $516 $100 $92 $256 
2022186 47 73 43 49 
2023137 34 49 57 29 
2024142 36 36 40 24 
2025170 37 30 36 11 
Thereafter1,824 79 111 107 80 
Total$2,624 $749 $399 $375 $449 
v3.20.4
Equity (Tables)
12 Months Ended
Dec. 31, 2020
Stockholders' Equity Note [Abstract]  
Schedule of common stock outstanding
Changes in the number of shares of common stock issued and outstanding for the years ended December 31, 2020, 2019 and 2018 are reflected in the table below.
Shares
Issued
Treasury
Shares
Shares Outstanding
Balance at December 31, 2017428,398,802 — 428,398,802 
Shares issued (a) (b)97,639,105 — 97,639,105 
Shares retired(6,815)— (6,815)
Shares repurchased— (32,815,783)(32,815,783)
Balance at December 31, 2018526,031,092 (32,815,783)493,215,309 
Shares issued (a) (c)2,716,349 18,773,958 21,490,307 
Shares retired(6,106)— (6,106)
Shares repurchased— (27,001,399)(27,001,399)
Balance at December 31, 2019528,741,335 (41,043,224)487,698,111 
Shares issued (a)1,611,462 — 1,611,462 
Shares retired(3,685)— (3,685)
Balance at December 31, 2020530,349,112 (41,043,224)489,305,888 
____________
(a)Shares issued includes share awards granted to nonemployee directors.
(b)The year ended December 31, 2018 includes 94,409,573 shares issued in connection with the Merger (see Note 2).
(c)The year ended December 31, 2019 includes 18,773,958 treasury shares issued in connection with the settlement of all outstanding TEUs as discussed below.
Schedule of share repurchase program
In June 2018, we announced that the Board had authorized a share repurchase program under which up to $500 million of our outstanding common stock may be purchased, and this authorized amount was fully utilized in 2018. In November 2018, we announced that the Board had authorized an incremental share repurchase program under which up to $1.250 billion of our outstanding stock may be purchased, resulting in an aggregate $1.750 billion share repurchase program (collectively, Prior Share Repurchase Program). The Prior Share Repurchase Program was terminated on January 1, 2021. Shares of common stock repurchased under the Prior Share Repurchase Program for the years ended December 31, 2020, 2019 and 2018 are reflected in the table below.
$500 Million Board Authorization$1.250 Billion Board Authorization
Total Number of Shares RepurchasedAverage Price Paid ShareAmount Paid for Shares RepurchasedTotal Number of Shares RepurchasedAverage Price Paid ShareAmount Paid for Shares Repurchased
Year Ended December 31, 201821,421,925$23.36 $500 12,073,091$22.99 $278 
Year Ended December 31, 2019$— $— 26,322,166$24.34 $640 
Year Ended December 31, 2020— — — — 
Totals21,421,925$23.36 $500 38,395,257$23.91 $918 
v3.20.4
Fair Value Measurements (Tables)
12 Months Ended
Dec. 31, 2020
Fair Value Disclosures [Abstract]  
Schedule of assets and liabilities measured at fair value on a recurring basis
Assets and liabilities measured at fair value on a recurring basis consisted of the following at the respective balance sheet dates shown below:
December 31, 2020December 31, 2019
Level
1
Level
2
Level
3 (a)
Reclass (b)TotalLevel
1
Level
2
Level
3 (a)
Reclass (b)Total
Assets:
Commodity contracts$452 $201 $205 $76 $934 $1,047 $172 $239 $11 $1,469 
Interest rate swaps— 72 — — 72 — — — — — 
Nuclear decommissioning trust – equity securities (c)623 — — — 623 564 — — — 564 
Nuclear decommissioning trust – debt securities (c)— 618 — — 618 — 521 — — 521 
Sub-total$1,075 $891 $205 $76 2,247 $1,611 $693 $239 $11 2,554 
Assets measured at net asset value (d):
Nuclear decommissioning trust – equity securities (c)433 366 
Total assets$2,680 $2,920 
Liabilities:
Commodity contracts$578 $172 $183 $76 $1,009 $985 $439 $313 $11 $1,748 
Interest rate swaps— 404 — — 404 — 177 — — 177 
Total liabilities$578 $576 $183 $76 $1,413 $985 $616 $313 $11 $1,925 
____________
(a)See table below for description of Level 3 assets and liabilities.
(b)Fair values are determined on a contract basis, but certain contracts result in a current asset and a noncurrent liability, or vice versa, as presented in our consolidated balance sheets.
(c)The nuclear decommissioning trust investment is included in the other investments line in our consolidated balance sheets. See Note 21.
(d)The fair value amounts presented in this line are intended to permit reconciliation of the fair value hierarchy to the amounts presented in our consolidated balance sheets. Certain investments measured at fair value using the net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.
Schedule of fair value of the Level 3 assets and liabilities by major contract type (all related to commodity contracts) and the significant unobservable inputs used in the valuations
The following tables present the fair value of the Level 3 assets and liabilities by major contract type and the significant unobservable inputs used in the valuations at December 31, 2020 and 2019:
December 31, 2020
Fair Value
Contract Type (a)AssetsLiabilitiesTotalValuation TechniqueSignificant Unobservable InputRange (b)Average (b)
Electricity purchases and sales$61 $(90)$(29)Income ApproachHourly price curve shape (c)$— to$85 $43 
MWh
Illiquid delivery periods for hub power prices and heat rates (d)$25 to$125 $75 
MWh
Options38 (56)(18)Option Pricing ModelGas to power correlation (e)30 %to100 %64 %
Power and gas volatility (e)%to665 %336 %
Financial transmission rights92 (16)76 Market Approach (f)Illiquid price differences between settlement points (g)$(5)to$50 $22 
MWh
Other (h)14 (21)(7)
Total$205 $(183)$22 

December 31, 2019
Fair Value
Contract Type (a)AssetsLiabilitiesTotalValuation TechniqueSignificant Unobservable InputRange (b)Average (b)
Electricity purchases and sales$64 $(53)$11 Income ApproachHourly price curve shape (c)$— to$115 $58 
MWh
Illiquid delivery periods for ERCOT hub power prices and heat rates (d)$20 to$120 $70 
MWh
Options38 (188)(150)Option Pricing ModelGas to power correlation (e)10 %to100 %55 %
Power and gas volatility (e)%to440 %223 %
Financial transmission rights120 (26)94 Market Approach (f)Illiquid price differences between settlement points (g)$(10)to$40 $15 
MWh
Other (h)17 (46)(29)
Total$239 $(313)$(74)
____________
(a)Electricity purchase and sales contracts include power and heat rate positions in ERCOT, PJM, ISO-NE, NYISO and MISO regions. The forward purchase contracts (swaps and options) used to hedge electricity price differences between settlement points are referred to as congestion revenue rights (CRRs) in ERCOT and financial transmission rights (FTRs) in PJM, ISO-NE, NYISO and MISO regions. Options consist of physical electricity options, spread options, swaptions and natural gas options.
(b)The range of the inputs may be influenced by factors such as time of day, delivery period, season and location. The average represents the arithmetic average of the underlying inputs and is not weighted by the related fair value or notional amount.
(c)Primarily based on the historical range of forward average hourly ERCOT North Hub prices.
(d)Primarily based on historical forward ERCOT and PJM power prices and ERCOT heat rate variability.
(e)Primarily based on the historical forward correlation and volatility within ERCOT.
(f)While we use the market approach, there is insufficient market data to consider the valuation liquid.
(g)Primarily based on the historical price differences between settlement points within ERCOT hubs and load zones.
(h)Other includes contracts for natural gas, coal and environmental allowances.
Schedule of changes in fair value of the Level 3 assets and liabilities
The following table presents the changes in fair value of the Level 3 assets and liabilities for the years ended December 31, 2020, 2019 and 2018.
Year Ended December 31,
202020192018
Net liability balance at beginning of period$(74)$(135)$(53)
Total unrealized valuation gains (losses)(5)(363)
Purchases, issuances and settlements (a):
Purchases164 176 146 
Issuances(28)(81)(41)
Settlements(90)(64)76 
Transfers into Level 3 (b)(2)10 
Transfers out of Level 3 (b)57 12 133 
Net liabilities assumed in connection with the Merger— — (37)
Net change (c)96 61 (82)
Net asset (liability) balance at end of period$22 $(74)$(135)
Unrealized valuation gains (losses) relating to instruments held at end of period$18 $(61)$(174)
____________
(a)Settlements reflect reversals of unrealized mark-to-market valuations previously recognized in net income. Purchases and issuances reflect option premiums paid or received, including CRRs and FTRs.
(b)Includes transfers due to changes in the observability of significant inputs. All Level 3 transfers during the periods presented are in and out of Level 2. For the year ended December 31, 2020, transfers out of Level 3 primarily consist of gas, power and coal derivatives where forward pricing inputs have become observable. For the years ended December 31, 2019 and 2018, transfers out of Level 3 primarily consist of power and coal derivatives where forward pricing inputs have become observable.
(c)Activity excludes change in fair value in the month positions settle. Substantially all changes in values of commodity contracts (excluding the net liabilities assumed in connection with the Merger) are reported as operating revenues in our consolidated statements of operations.
v3.20.4
Commodity And Other Derivative Contractual Assets And Liabilities (Tables)
12 Months Ended
Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Schedule of commodity and other derivative contractual assets and liabilities as reported in the balance sheets
Substantially all derivative contractual assets and liabilities are accounted for under mark-to-market accounting consistent with accounting standards related to derivative instruments and hedging activities. The following tables provide detail of derivative contractual assets and liabilities as reported in our consolidated balance sheets at December 31, 2020 and 2019. Derivative asset and liability totals represent the net value of the contract, while the balance sheet totals represent the gross value of the contract.
December 31, 2020
Derivative AssetsDerivative Liabilities
Commodity ContractsInterest Rate SwapsCommodity ContractsInterest Rate SwapsTotal
Current assets$665 $19 $64 $— $748 
Noncurrent assets197 53 — 258 
Current liabilities(1)— (717)(71)(789)
Noncurrent liabilities(3)— (288)(333)(624)
Net assets (liabilities)$858 $72 $(933)$(404)$(407)

December 31, 2019
Derivative AssetsDerivative Liabilities
Commodity ContractsInterest Rate SwapsCommodity ContractsInterest Rate SwapsTotal
Current assets$1,323 $— $10 $— $1,333 
Noncurrent assets136 — — — 136 
Current liabilities(1)— (1,510)(18)(1,529)
Noncurrent liabilities— — (237)(159)(396)
Net assets (liabilities)$1,458 $— $(1,737)$(177)$(456)
Schedule of pretax effect on net income of derivatives not under hedge accounting, including realized and unrealized effects
The following table presents the pretax effect of derivative gains (losses) on net income, including realized and unrealized effects. Amount represents changes in fair value of positions in the derivative portfolio during the period, as realized amounts related to positions settled are assumed to equal reversals of previously recorded unrealized amounts.

Year Ended December 31,
Derivative (consolidated statements of operations presentation)202020192018
Commodity contracts (Operating revenues)$241 $339 $(855)
Commodity contracts (Fuel, purchased power costs and delivery fees)(1)18 
Interest rate swaps (Interest expense and related charges)(196)(217)(11)
Net gain (loss)$49 $121 $(848)
Schedule of offsetting assets and liabilities
The following tables reconcile our derivative assets and liabilities on a contract basis to net amounts after taking into consideration netting arrangements with counterparties and financial collateral:
December 31, 2020December 31, 2019
Derivative Assets
and Liabilities
Offsetting Instruments (a)Cash Collateral (Received) Pledged (b)Net AmountsDerivative Assets
and Liabilities
Offsetting Instruments (a)Cash Collateral (Received) Pledged (b)Net Amounts
Derivative assets:
Commodity contracts$858 $(667)$(11)$180 $1,458 $(1,113)$— $345 
Interest rate swaps72 (72)— — — — — — 
Total derivative assets930 (739)(11)180 1,458 (1,113)— 345 
Derivative liabilities:
Commodity contracts(933)667 138 (128)(1,737)1,113 40 (584)
Interest rate swaps(404)72 — (332)(177)— — (177)
Total derivative liabilities(1,337)739 138 (460)(1,914)1,113 40 (761)
Net amounts$(407)$— $127 $(280)$(456)$— $40 $(416)
____________
(a)Amounts presented exclude trade accounts receivable and payable related to settled financial instruments.
(b)Represents cash amounts received or pledged pursuant to a master netting arrangement, including fair value-based margin requirements, and, to a lesser extent, initial margin requirements.
Schedule of gross notional amounts of derivative volumes
The following table presents the gross notional amounts of derivative volumes at December 31, 2020 and 2019:
December 31, 2020December 31, 2019
Derivative typeNotional VolumeUnit of Measure
Natural gas (a)5,264 6,160 Million MMBtu
Electricity438,863 428,367 GWh
Financial transmission rights (b)217,350 199,648 GWh
Coal20 22 Million U.S. tons
Fuel oil176 33 Million gallons
Emissions20 Million tons
Renewable energy certificates18 11 Million certificates
Interest rate swaps – variable/fixed (c)$6,720 $6,720 Million U.S. dollars
Interest rate swaps - fixed/variable (c)$2,120 $2,120 Million U.S. dollars
____________
(a)Represents gross notional forward sales, purchases and options transactions, locational basis swaps and other natural gas transactions.
(b)Represents gross forward purchases associated with instruments used to hedge electricity price differences between settlement points within regions.
(c)Includes notional amounts of interest rate swaps with maturity dates through July 2026.
Credit risk-related contingent features of derivatives
The following table presents the commodity derivative liabilities subject to credit risk-related contingent features that are not fully collateralized:
December 31,
20202019
Fair value of derivative contract liabilities (a)$(679)$(692)
Offsetting fair value under netting arrangements (b)262 167 
Cash collateral and letters of credit35 67 
Liquidity exposure$(382)$(458)
____________
(a)Excludes fair value of contracts that contain contingent features that do not provide specific amounts to be posted if features are triggered, including provisions that generally provide the right to request additional collateral (material adverse change, performance assurance and other clauses).
(b)Amounts include the offsetting fair value of in-the-money derivative contracts and net accounts receivable under master netting arrangements.
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Tables)
12 Months Ended
Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans  
Schedule of Pension and OPEB Costs [Table Text Block]
Pension and OPEB Costs
Year Ended December 31,
202020192018
Pension costs$11 $$14 
OPEB costs11 
Total benefit costs recognized as expense$18 $20 $23 
Schedule of Defined Benefit Plans Disclosures [Table Text Block]
At December 31, 2020 and 2019, all of the Retirement Plan assets were measured at fair value using the net asset value per share (or its equivalent) and consisted of the following:
Year Ended December 31,
20202019
Asset Category:
Cash commingled trusts11 10 
Equity securities:
Global equities153 169 
Fixed income securities:
Corporate bonds (a)207 211 
Government bonds37 50 
Other (b)32 37 
Real estate45 51 
Total assets measured at net asset value$485 $528 
___________
(a)Substantially all corporate bonds are rated investment grade by a major ratings agency such as Moody's.
(b)Consists primarily of high-yield bonds, emerging market debt and bank loans.
Schedule of Accumulated and Projected Benefit Obligations [Table Text Block]
The following table provides information regarding pension plans with projected benefit obligation (PBO) and accumulated benefit obligation (ABO) in excess of the fair value of plan assets.
December 31,
20202019
Pension Plans with PBO and ABO in Excess Of Plan Assets:
Projected benefit obligations$643 $674 
Accumulated benefit obligation$639 $669 
Plan assets$485 $528 
Schedule of Allocation of Plan Assets [Table Text Block]
Pension Plan Investment Strategy and Asset Allocations

Our investment objective for the Retirement Plan is to invest in a suitable mix of assets to meet the future benefit obligations at an acceptable level of risk, while minimizing the volatility of contributions. Fixed income securities held primarily consist of corporate bonds from a diversified range of companies, U.S. Treasuries and agency securities and money market instruments. Equity securities are held to enhance returns by participating in a wide range of investment opportunities. International equity securities are used to further diversify the equity portfolio and may include investments in both developed and emerging markets. Real estate and credit strategies (primarily high yield bonds and emerging market debt) provide additional portfolio diversification and return potential.

The target asset allocation ranges of pension plan investments by asset category are as follows:
Target Allocation Ranges
Asset Category:Vistra PlanDynegy PlanEEI Plan
Fixed income65 %-75%45 %-55%40 %-50%
Global equity securities16 %-24%30 %-38%34 %-42%
Real estate%-8%%-12%10 %-14%
Credit strategies%-7%%-10%%-11%
Defined Benefit Plan, Assumptions [Table Text Block]
Expected Long-Term Rate of Return on Assets Assumption

The Retirement Plan strategic asset allocation is determined in conjunction with the plan's advisors and utilizes a comprehensive Asset-Liability modeling approach to evaluate potential long-term outcomes of various investment strategies. The study incorporates long-term rate of return assumptions for each asset class based on historical and future expected asset class returns, current market conditions, rate of inflation, current prospects for economic growth, and taking into account the diversification benefits of investing in multiple asset classes and potential benefits of employing active investment management.
Retirement Plan
Expected Long-Term Rate of Return
Asset Class:Vistra PlanDynegy PlanEEI Plan
Fixed income securities2.4 %2.3 %2.3 %
Global equity securities7.3 %7.3 %7.3 %
Real estate5.6 %5.6 %5.6 %
Credit strategies4.8 %4.8 %4.8 %
Weighted average3.8 %4.4 %4.7 %
Schedule of Health Care Cost Trend Rates [Table Text Block]
The following tables provide information regarding the assumed health care cost trend rates.
December 31, 2020December 31, 2019
Assumed Health Care Cost Trend Rates-Not Medicare Eligible:
Health care cost trend rate assumed for next year6.20 %6.40 %
Rate to which the cost trend is expected to decline (the ultimate trend rate)4.50 %4.50 %
Year that the rate reaches the ultimate trend rate20292029
Assumed Health Care Cost Trend Rates-Medicare Eligible:
Health care cost trend rate assumed for next year (Vistra Plan, EEI Union and EEI Salaried)9.10 %8.60 %
Health care cost trend rate assumed for next year (Split-Participant Plan)8.80 %8.30 %
Rate to which the cost trend is expected to decline (the ultimate trend rate)4.50 %4.50 %
Year that the rate reaches the ultimate trend rate20302029
Schedule of Expected Benefit Payments [Table Text Block]
Future Benefit Payments

Estimated future benefit payments to beneficiaries are as follows:
202120222023202420252026-2030
Pension benefits$49 $43 $43 $40 $52 $188 
OPEB$10 $10 $10 $10 $$41 
Pension Plan [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Schedule of Defined Benefit Plans Disclosures [Table Text Block]
Detailed Information Regarding Pension Benefits

The following information is based on a December 31, 2020, 2019 and 2018 measurement dates:
Year Ended December 31,
202020192018
Assumptions Used to Determine Net Periodic Pension Cost:
Discount rate (Vistra Plan)3.24 %4.37 %3.74 %
Discount rate (Dynegy Plan and EEI Plan)3.24 %4.37 %4.05 %
Expected return on plan assets (Vistra Plan)4.44 %4.80 %4.56 %
Expected return on plan assets (Dynegy Plan)5.28 %5.31 %5.94 %
Expected return on plan assets (EEI Plan)5.45 %5.56 %4.74 %
Expected rate of compensation increase (Vistra Plan)3.29 %3.35 %3.62 %
Expected rate of compensation increase (Dynegy Plan and EEI Plan)3.29 %3.35 %3.50 %
Interest crediting rate for cash balance plans (Vistra Plan)3.50 %3.50 %3.50 %
Interest crediting rate for cash balance plans (Dynegy Plan and EEI Plan)3.50 %3.50 %4.25 %
Components of Net Pension Cost:
Service cost$$$15 
Interest cost20 25 21 
Expected return on assets(23)(26)(23)
Amortization of unrecognized amounts— — 
Immediate pension cost
Net periodic pension cost$11 $$14 
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income:
Net loss$17 $11 $14 
Total recognized in net periodic benefit cost and other comprehensive income$28 $20 $28 
Assumptions Used to Determine Benefit Obligations:
Discount rate2.50 %3.24 %4.37 %
Expected rate of compensation increase3.41 %3.29 %3.35 %
Interest crediting rate for cash balance plans3.00 %3.50 %3.50 %

For the year ended December 31, 2020, the net actuarial loss of $29 million was driven by losses attributable to decreasing discount rates due to changes in the corporate bond markets, actuarial assumption updates to reflect current market conditions and plan amendments, partially offset by gains attributable to actual asset performance exceeding expectations, life expectancy updates, annuity purchases, lump sum windows and plan experience different than expected.

For the year ended December 31, 2019, the net actuarial loss of $16 million was driven by losses attributable to decreasing discount rates due to changes in the corporate bond markets, actuarial assumption updates to reflect current market conditions, annuity purchases, plan amendments and plan experience different than expected, partially offset by gains attributable to actual asset performance exceeding expectations and life expectancy updates.

For the year ended December 31, 2018, the net actuarial loss of $14 million was driven by losses attributable to actual asset performance falling short of expectations and plan experience different than expected, partially offset by gains attributable to increasing discount rates due to changes in the corporate bond markets, economic assumption updates to reflect current market conditions and life expectancy projection updates.
Year Ended December 31,
20202019
Change in Pension Obligation:
Projected benefit obligation at beginning of period$674 $615 
Service cost
Interest cost20 25 
Lump-sum window(6)— 
Annuity purchase(29)(18)
Actuarial loss46 93 
Benefits paid(68)(48)
Projected benefit obligation at end of year$643 $674 
Accumulated benefit obligation at end of year$639 $669 
Change in Plan Assets:
Fair value of assets at beginning of period$528 $490 
Employer contributions16 — 
Lump-sum window(6)— 
Annuity purchase(29)(18)
Actual gain on assets40 102 
Benefits paid(64)(46)
Fair value of assets at end of year$485 $528 
Funded Status:
Projected pension benefit obligation$(643)$(674)
Fair value of assets485 528 
Funded status at end of year$(158)$(146)
Amounts Recognized in the Balance Sheet Consist of:
Other noncurrent liabilities$(158)$(146)
Net liability recognized$(158)$(146)
Amounts Recognized in Accumulated Other Comprehensive Income Consist of:
Net (loss)$(42)$(24)
Other Postretirement Benefits Plan [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Defined Benefit Plan, Assumptions [Table Text Block]
Detailed Information Regarding Postretirement Benefits Other Than Pensions

The following OPEB information is based on a December 31, 2020 measurement date:
Year Ended December 31,
202020192018
Assumptions Used to Determine Net Periodic Benefit Cost:
Discount rate (Vistra Plan)3.25 %4.35 %3.67 %
Discount rate (Split-Participant Plan)3.25 %4.35 %3.67 %
Discount rate (Dynegy Plan)3.25 %4.35 %4.04 %
Expected return on plan assets (EEI Union)7.07 %5.36 %5.10 %
Expected return on plan assets (EEI Salaried)3.43 %4.70 %4.47 %
Components of Net Postretirement Benefit Cost:
Service cost$$$
Interest cost
Expected return on plan assets(2)(1)(1)
Amortization of unrecognized amounts
Immediate postretirement benefit cost(1)— 
Net periodic OPEB cost$$11 $
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income:
Net (gain) loss and prior service (credit) cost$$— $(6)
Total recognized in net periodic benefit cost and other comprehensive income$12 $11 $
Assumptions Used to Determine Benefit Obligations at Period End:
Discount rate2.51 %3.25 %4.35 %

For the year ended December 31, 2020, the net actuarial loss of $10 million was driven by losses attributable to decreasing discount rates due to changes in the corporate bond markets and plan experience different than expected, partially offset by gains attributable to actual asset performance exceeding expectations, life expectancy updates and updates to health care claims and trend assumptions.

For the year ended December 31, 2019, the net actuarial loss of $5 million was driven by losses attributable to decreasing discount rates due to changes in the corporate bond markets and plan experience different than expected, partially offset by gains attributable to actual asset performance exceeding expectations, life expectancy changes, updates to health care related assumptions and changes due to the repeal of certain Affordable Care Act fees.

For the period ended December 31, 2018, the net actuarial loss of $7 million was driven by gains attributable to increasing discount rates due to changes in the corporate bond markets, life expectancy projection updates and updates to health care related assumptions, partially offset by losses attributable to actual asset performance falling short of expectations and plan experience different than expected.
Year Ended December 31,
20202019
Change in Postretirement Benefit Obligation:
Benefit obligation at beginning of year$151 $144 
Service cost
Interest cost
Participant contributions
Actuarial loss12 10 
Benefits paid(15)(14)
Benefit obligation at end of year$157 $151 
Change in Plan Assets:
Fair value of assets at beginning of year$34 $29 
Employer contributions
Participant contributions
Benefits paid(13)(13)
Actual gain on assets
Fair value of assets at end of year$37 $34 
Funded Status:
Benefit obligation$(157)$(151)
Fair value of assets37 34 
Funded status at end of year$(120)$(117)
Amounts Recognized on the Balance Sheet Consist of:
Other noncurrent assets$23 $18 
Other current liabilities$(9)$(9)
Other noncurrent liabilities(134)(126)
Net liability recognized$(120)$(117)
Amounts Recognized in Accumulated Other Comprehensive Income Consist of:
Net loss and prior service cost$20 $15 
v3.20.4
Stock-Based Compensation (Tables)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share-based Payment Arrangement [Abstract]    
Schedule of stock-based compensation awards assumed in Merger
At the Merger Date, Dynegy stock options and equity-based awards outstanding immediately prior to the Merger Date were generally automatically converted upon completion of the Merger into stock options and equity-based awards, respectively, with respect to Vistra's common stock, after giving effect to the Exchange Ratio.
Instrument TypeDynegy Awards Prior to the Merger DateVistra Awards Converted at the Merger DateFair Value of Awards (a) at the Merger Date
Stock Options4,096,027 2,670,610 $10 
Restricted Stock Units5,718,148 3,056,689 61 
Performance Units1,538,133 938,721 18 
Total$89 
____________
(a)$26 million was attributable to pre-combination service and considered part of the purchase price (see Note 2). $33 million was recognized immediately as compensation expense due to accelerated vesting as a result of the Merger. $30 million will be amortized as compensation expense over the remaining service period and is recorded in additional paid in capital in the consolidated balance sheet.
 
Schedule of stock-based compensation expense recorded
Stock-based compensation expense is reported as SG&A in the consolidated statements of operations as follows:
Year Ended December 31,
202020192018
Total stock-based compensation expense$63 $47 $73 
Income tax benefit(15)(9)(15)
Stock based-compensation expense, net of tax$48 $38 $58 
 
Schedule of stock-based compensation stock options activity
Stock options outstanding at December 31, 2020 are all held by current or former employees. The following table summarizes our stock option activity:
Year Ended December 31, 2020
Stock Options
(in thousands)
Weighted
Average Exercise Price
Weighted Average Remaining Contractual Term (Years)Aggregate Intrinsic Value (in millions)
Total outstanding at beginning of period13,535 $18.73 7.3$69.3 
Granted3,014 $22.98 
Exercised(251)$13.62 
Forfeited or expired(268)$20.74 
Total outstanding at end of period16,030 $19.58 6.7$30.8 
Exercisable at December 31, 20206,871 $16.83 5.9$30.5 
 
Schedule of share-based compensation, restricted stock units award activity  
The following table summarizes our restricted stock unit activity:
Year Ended December 31, 2020
Restricted Stock Units
(in thousands)
Weighted
Average Grant Date Fair Value
Total nonvested at beginning of period2,538 $20.99 
Granted1,209 $22.50 
Vested(1,456)$19.48 
Forfeited(39)$21.89 
Total nonvested at end of period2,252 $22.35 
v3.20.4
Segment Information (Tables)
12 Months Ended
Dec. 31, 2020
Segment Reporting [Abstract]  
Schedule of segment reporting information, by segment

For the year ended
RetailTexasEastWestSunsetAsset ClosureCorporate and Other (b)EliminationsConsolidated
Operating revenues (a):
December 31, 2020$8,270 $4,116 $2,415 $282 $1,252 $$— $(4,895)$11,443 
December 31, 20196,872 3,836 2,790 338 1,602 341 — (3,970)11,809 
December 31, 20185,597 2,497 1,895 208 1,183 371 — (2,607)9,144 
Depreciation and amortization:
December 31, 2020$(303)$(475)$(721)$(19)$(133)$(22)$(64)$— $(1,737)
December 31, 2019(292)(472)(680)(19)(120)— (57)— (1,640)
December 31, 2018(318)(390)(519)(14)(81)— (72)— (1,394)
Operating income (loss):
December 31, 2020$312 $1,761 $73 $39 $(420)$(109)$(137)$— $1,519 
December 31, 2019155 1,314 398 88 271 (107)(127)1,993 
December 31, 2018690 (103)10 35 242 (63)(320)— 491 
Interest expense and related charges:
December 31, 2020$(10)$$(7)$10 $(2)$— $(632)$$(630)
December 31, 2019(21)(13)— (4)— (770)(797)
December 31, 2018(7)(12)(10)(1)(1)— (612)71 (572)
Income tax (expense) benefit:
December 31, 2020$— $— $— $— $— $— $(266)$— $(266)
December 31, 2019— — — — — — (290)— (290)
December 31, 2018— — — — — — 45 — 45 
Net income (loss):
December 31, 2020$309 $1,760 $41 $50 $(414)$(101)$(1,021)$— $624 
December 31, 2019134 1,342 400 88 274 (109)(1,204)926 
December 31, 2018712 (88)18 34 242 (62)(912)— (56)
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures:
December 31, 2020$$388 $71 $$46 $— $91 $— $600 
December 31, 2019296 61 58 — 69 — 487 
December 31, 2018280 21 36 — 50 — 396 
____________
(a)The following unrealized net gains (losses) from mark-to-market valuations of commodity positions are included in operating revenues:
For the year endedRetailTexasEastWestSunsetAsset ClosureCorporate and OtherEliminations (1)Consolidated
December 31, 2020$(11)$677 $(23)$(10)$(140)$— $— $(329)$164 
December 31, 2019575 195 41 168 — — (305)682 
December 31, 2018(12)(483)(76)(15)(11)— — 217 (380)
____________
(1) Amounts offset in fuel, purchased power costs and delivery fees in the Retail segment, with no impact to consolidated results.
(b)Income tax expense is not reflected in net income of the segments but is reflected entirely in Corporate and Other net income.
v3.20.4
Supplementary Financial Information (Tables)
12 Months Ended
Dec. 31, 2020
Supplementary Financial Information [Abstract]  
Schedule of interest expense and related charges
Interest Expense and Related Charges
Year Ended December 31,
202020192018
Interest paid/accrued$467 $576 $537 
Unrealized mark-to-market net losses on interest rate swaps155 220 
Amortization of debt issuance costs, discounts and premiums18 — 
Debt extinguishment (gain) loss(17)(21)27 
Capitalized interest(21)(12)(12)
Other28 25 15 
Total interest expense and related charges$630 $797 $572 

The weighted average interest rate applicable to the Vistra Operations Credit Facilities, taking into account the interest rate swaps discussed in Note 11, was 3.88%, 4.03% and 4.24% at December 31, 2020, 2019 and 2018, respectively.
Schedule of other income and deductions
Other Income and Deductions
Year Ended December 31,
202020192018
Other income:
Insurance settlement (a)$$22 $16 
Funds released from escrow to settle pre-petition claims of our predecessor (b)— — 
Office space sublease rental income (b)— — 
Sale of land (c)— 
Interest income10 18 
All other18 15 
Total other income$34 $56 $47 
Other deductions:
Loss on disposal of investment in NELP (d)$29 $— $— 
All other13 15 
Total other deductions$42 $15 $
____________
(a)For the year ended December 31, 2020, $3 million reported in the Corporate and Other non-segment, $2 million reported in the Asset Closure segment and $1 million reported in the Texas segment. The amounts for the years ended December 31, 2019 and 2018, respectively, are reported in the Texas segment.
(b)Reported in the Corporate and Other non-segment. Beginning January 1, 2019, our office space sublease rental income related to real estate leases is reported in SG&A expenses in the consolidated statements of operations.
(c)For the year ended December 31, 2020, reported in the Asset Closure segment. For the year ended December 31, 2018, reported in the Texas segment.
(d)Reported in the East segment.
Schedule of restricted cash
Restricted Cash
December 31, 2020December 31, 2019
Current
Assets
Noncurrent AssetsCurrent
Assets
Noncurrent Assets
Amounts related to remediation escrow accounts$19 $19 $15 $28 
Amounts related to restructuring escrow accounts— — 43 — 
Amounts related to Ambit customer deposits— — 19 — 
Amounts related to Ambit commodity trading agreement— — 62 — 
Amounts related to Ambit letters of credit (Note 11)— — — 
Total restricted cash$19 $19 $147 $28 
Schedule of accounts, notes, loans and financing receivable
Trade Accounts Receivable
December 31,
20202019
Wholesale and retail trade accounts receivable$1,324 $1,401 
Allowance for uncollectible accounts(45)(36)
Trade accounts receivable — net$1,279 $1,365 

Gross trade accounts receivable at December 31, 2020 and 2019 included unbilled retail revenues of $468 million and $494 million, respectively.

Allowance for Uncollectible Accounts Receivable
Year Ended December 31,
202020192018
Allowance for uncollectible accounts receivable at beginning of period (a)$42 $19 $14 
Increase for bad debt expense110 82 56 
Decrease for account write-offs(107)(65)(51)
Allowance for uncollectible accounts receivable at end of period$45 $36 $19 
____________
(a)Includes a $6 million increase recorded due to the adoption of ASU 2016-13, Financial Instruments—Credit Losses (see Note 1).
Schedule of inventories by major category
Inventories by Major Category
December 31,
20202019
Materials and supplies$260 $278 
Fuel stock236 172 
Natural gas in storage19 19 
Total inventories$515 $469 
Summary of other investments
Investments
December 31,
20202019
Nuclear plant decommissioning trust$1,674 $1,451 
Assets related to employee benefit plans (Note 17)41 37 
Land44 49 
Total investments$1,759 $1,537 
Summary of investments in the fund A summary of the fair market value of investments in the fund follows:
Year Ended December 31,
20202019
Debt securities (a)$618 $521 
Equity securities (b)1,056 930 
Total$1,674 $1,451 
____________
(a)The investment objective for debt securities is to invest in a diversified tax efficient portfolio with an overall portfolio rating of AA or above as graded by S&P or Aa2 by Moody's. The debt securities are heavily weighted with government and municipal bonds and investment grade corporate bonds. The debt securities had an average coupon rate of 2.91% and 3.42% at December 31, 2020 and 2019, respectively, and an average maturity of 10 years and 9 years at December 31, 2020 and 2019, respectively.
(b)The investment objective for equity securities is to invest tax efficiently and to match the performance of the S&P 500 Index for U.S. equity investments and the MSCI EAFE Index for non-U.S. equity investments.
Summary of proceeds from sales of available-for-sale securities and the related realized gains and losses from such sales The following table summarizes proceeds from sales of securities and investments in new securities.
Year Ended December 31,
202020192018
Proceeds from sales of securities$433 $431 $252 
Investments in securities$(455)$(453)$(274)
Schedule of property, plant and equipment
Property, Plant and Equipment
December 31,
20202019
Power generation and structures$15,222 $15,205 
Land617 622 
Office and other equipment173 164 
Total16,012 15,991 
Less accumulated depreciation(3,614)(2,553)
Net of accumulated depreciation12,398 13,438 
Finance lease right-of-use assets (net of accumulated depreciation)182 59 
Nuclear fuel (net of accumulated amortization of $91 million and $216 million)
207 197 
Construction work in progress712 220 
Property, plant and equipment — net$13,499 $13,914 

Depreciation expenses totaled $1.377 billion, $1.300 billion and $1.024 billion for the years ended December 31, 2020, 2019 and 2018, respectively.

Our property, plant and equipment consist of our power generation assets, related mining assets, information system hardware, capitalized corporate office lease space and other leasehold improvements. The estimated remaining useful lives range from 1 to 33 years for our property, plant and equipment.
Schedule of asset retirement and mining reclamation obligations The following table summarizes the changes to these obligations, reported as AROs (current and noncurrent liabilities) in our consolidated balance sheets, for the years ended December 31, 2020, 2019 and 2018:
Nuclear Plant DecommissioningMining Land ReclamationCoal Ash and OtherTotal
Liability at December 31, 2017$1,233 $438 $265 $1,936 
Additions:
Accretion43 22 28 93 
Adjustment for change in estimates— 56 (89)(33)
Obligations assumed in the Merger— 475 477 
Reductions:
Payments— (76)(24)(100)
Liability at December 31, 20181,276 442 655 2,373 
Additions:
Accretion44 22 31 97 
Adjustment for change in estimates— 16 (1)15 
Adjustment for obligations assumed through acquisitions— — (3)(3)
Reductions:
Payments— (70)(39)(109)
Liability transfers (a)— — (135)(135)
Liability at December 31, 20191,320 410 508 2,238 
Additions:
Accretion46 20 23 89 
Adjustment for change in estimates (b)219 (6)25 238 
Reductions:
Payments— (65)(49)(114)
Liability transfers (a)— — (15)(15)
Liability at December 31, 20201,585 359 492 2,436 
Less amounts due currently— (92)(11)(103)
Noncurrent liability at December 31, 2020$1,585 $267 $481 $2,333 
____________
(a)Represents ARO transferred to a third-party for remediation. Any remaining unpaid third-party obligation has been reclassified to other current liabilities and other noncurrent liabilities and deferred credits in our consolidated balance sheets.
(b)The adjustment for nuclear plant decommissioning resulted from a new cost estimate completed in 2020. Under applicable accounting standards, the liability is remeasured when significant changes in the amount or timing of cash flows occur, and the PUCT requires a new cost estimate at least every five years. The increase in the liability was driven by changes in assumptions including increased costs for labor, equipment and services and a delay in timing of when the U.S. Department of Energy is estimated to begin accepting spent fuel offsite.
Schedule of other noncurrent liabilities and deferred credits
Other Noncurrent Liabilities and Deferred Credits

The balance of other noncurrent liabilities and deferred credits consists of the following:
December 31,
20202019
Retirement and other employee benefits (Note 17)$312 $295 
Identifiable intangible liabilities (Note 6)289 286 
Regulatory liability89 131 
Finance lease liabilities206 78 
Uncertain tax positions, including accrued interest12 10 
Liability for third-party remediation31 41 
Environmental allowances— 52 
Accrued severance costs54 12 
Other accrued expenses138 84 
Total other noncurrent liabilities and deferred credits$1,131 $989 
Schedule of fair value of debt
Fair Value of Debt
December 31, 2020December 31, 2019
Long-term debt (see Note 11):Fair Value HierarchyCarrying AmountFair
Value
Carrying AmountFair
Value
Long-term debt under the Vistra Operations Credit FacilitiesLevel 2$2,579 $2,565 $2,715 $2,717 
Vistra Operations Senior NotesLevel 26,634 7,204 6,620 6,926 
Vistra Senior NotesLevel 2— — 774 772 
Forward Capacity AgreementsLevel 345 45 155 155 
Equipment Financing AgreementsLevel 359 59 87 87 
Building FinancingLevel 210 10 16 16 
Other debtLevel 312 12 
Schedule of supplemental cash flow information
Supplemental Cash Flow Information

The following table reconciles cash, cash equivalents and restricted cash reported in our consolidated statements of cash flows to the amounts reported in our consolidated balance sheets at December 31, 2020 and 2019:
December 31,
20202019
Cash and cash equivalents$406 $300 
Restricted cash included in current assets19 147 
Restricted cash included in noncurrent assets19 28 
Total cash, cash equivalents and restricted cash$444 $475 
The following table summarizes our supplemental cash flow information for the years ended December 31, 2020, 2019 and 2018, respectively.
Year Ended December 31,
202020192018
Cash payments related to:
Interest paid$503 $525 $651 
Capitalized interest(21)(12)(12)
Interest paid (net of capitalized interest)$482 $513 $639 
Income taxes paid / (refunds received) (a)$(140)$(76)$67 
Noncash investing and financing activities:
Accrued property, plant and equipment additions (b)$19 $67 $84 
Disposition of investment in NELP$123 $— $— 
Acquisition of investment in NJEA$90 $— $— 
Shares issued for tangible equity unit contracts (Note 14)$— $446 $— 
Land transferred with liability transfers$— $16 $— 
Vistra common stock issued in the Merger (Notes 2 and 14)$— $— $2,245 
____________
(a)For the years ended December 31, 2020, 2019 and 2018, we paid federal income taxes of zero, zero and $45 million, respectively, paid state income taxes of $40 million, $42 million and $27 million, respectively, received federal tax refunds of $170 million, $115 million and zero, respectively, and received state tax refunds of $10 million, $3 million and $5 million, respectively.
(b)Represents property, plant and equipment accruals during the period for which cash has not been paid as of the end of the period.
v3.20.4
Business And Significant Accounting Policies (Narrative) (Details)
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
Reportable_segment
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Apr. 09, 2018
USD ($)
Number of reportable segments (in reportable segments) | Reportable_segment 6      
Advertising expense $ 43 $ 49 $ 46  
Operating loss and alternative minimum tax carryforwards acquired in Merger       $ 4,500
Luminant Generation Company LLC [Member] | Upton County 2 Solar Facility [Member]        
Reduction of tax basis of asset, use of investment tax credit deferral method $ 0 $ 2 $ 78  
Electric Energy, Inc. [Member]        
Noncontrolling interest, ownership percentage by noncontrolling owners 20.00%      
v3.20.4
Business And Significant Accounting Policies (Adoption of New Accounting Standards) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Operating lease right-of-use asset $ 227 $ 103    
Lease liabilities 262 141    
Other comprehensive income impact of adoption of new accounting standard $ 0 $ 0 $ 1  
Accounting Standards Update 2016-02 [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Operating lease right-of-use asset       $ 85
Lease liabilities       $ 123
Reclassification of income tax effects of tax cuts and jobs act within accumulated other comprehensive income to retained earnings per ASU 2018-02 [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Other comprehensive income impact of adoption of new accounting standard     $ 1  
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Ambit and Crius Transactions Narrative) (Details)
$ in Millions
12 Months Ended
Nov. 01, 2019
USD ($)
TW
Jul. 15, 2019
USD ($)
TW
Dec. 31, 2019
USD ($)
Ambit Transaction [Member]      
Business Acquisition [Line Items]      
Numbers of states in which entity operates 17    
Business Combination, consideration transferred $ 555    
Long-term debt, including amounts due currently 0    
Cash and cash equivalents $ 49    
Electricity load, annualized basis | TW 11    
Business Combination, acquisition related costs     $ 1
Business Combination, separately recognized transactions, revenues and gains recognized     193
Business Combination, separately recognized transactions, net gains and losses     2
Crius Transaction [Member]      
Business Acquisition [Line Items]      
Numbers of states in which entity operates   19  
Business Combination, consideration transferred   $ 400  
Business Combination, consideration transferred to acquire outstanding trust units   382  
Long-term debt, including amounts due currently   140  
Cash and cash equivalents   $ 26  
Electricity load, annualized basis | TW   10  
Business Combination, acquisition related costs     2
Business Combination, separately recognized transactions, revenues and gains recognized     453
Business Combination, separately recognized transactions, net gains and losses     $ 0
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Ambit and Crius Transactions Preliminary Purchase Price Allocation) (Details) - USD ($)
$ in Millions
11 Months Ended 12 Months Ended
Sep. 30, 2020
Jun. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Nov. 01, 2019
Jul. 15, 2019
Dec. 31, 2018
Goodwill     $ 2,583 $ 2,553     $ 2,068
Ambit Transaction [Member]              
Cash, cash equivalents and restricted cash         $ 49    
Net working capital         32    
Accumulated deferred income taxes         0    
Identifiable intangible assets         218    
Goodwill         258    
Commodity and other derivative contractual assets         23    
Other noncurrent assets         13    
Total assets acquired         593    
Identifiable intangible liabilities         0    
Long-term debt, including amounts due currently         0    
Commodity and other derivative contractual liabilities         28    
Accumulated deferred income taxes         0    
Other noncurrent liabilities         10    
Total liabilities assumed         38    
Identifiable net assets acquired         $ 555    
Cash and cash equivalents, period increase (decrease) $ 0            
Net working capital, period increase (decrease) 3            
Accumulated deferred income taxes, asset, period increase (decrease) 0            
Identifiable intangible assets, period increase (decrease) (45)            
Goodwill, period increase (decrease) 44            
Commodity and other derivative assets, period increase (decrease) 0            
Other noncurrent assets, period increase (decrease) 0            
Total assets acquired, period increase (decrease) 2            
Identifiable intangible liabilities, period increase (decrease) 0            
Long-term debt, including amounts due currently, period increase (decrease) 0            
Commodity and other derivative contractual liabilities, period increase (decrease) 0            
Accumulated deferred income taxes, liability, period increase (decrease) 0            
Other noncurrent liabilities, period increase (decrease) 2            
Total liabilities assumed, period increase (decrease) 2            
Identifiable net assets acquired, period increase (decrease) $ 0            
Crius Transaction [Member]              
Cash, cash equivalents and restricted cash           $ 26  
Net working capital           (9)  
Accumulated deferred income taxes           0  
Identifiable intangible assets           317  
Goodwill           243  
Commodity and other derivative contractual assets           18  
Other noncurrent assets           17  
Total assets acquired           612  
Identifiable intangible liabilities           2  
Long-term debt, including amounts due currently           140  
Commodity and other derivative contractual liabilities           40  
Accumulated deferred income taxes           14  
Other noncurrent liabilities           16  
Total liabilities assumed           212  
Identifiable net assets acquired           $ 400  
Cash and cash equivalents, period increase (decrease)   $ 0          
Net working capital, period increase (decrease)   (42)          
Accumulated deferred income taxes, asset, period increase (decrease)   (36)          
Identifiable intangible assets, period increase (decrease)   23          
Goodwill, period increase (decrease)   38          
Commodity and other derivative assets, period increase (decrease)   0          
Other noncurrent assets, period increase (decrease)   (3)          
Total assets acquired, period increase (decrease)   (20)          
Identifiable intangible liabilities, period increase (decrease)   (34)          
Long-term debt, including amounts due currently, period increase (decrease)   0          
Commodity and other derivative contractual liabilities, period increase (decrease)   0          
Accumulated deferred income taxes, liability, period increase (decrease)   14          
Other noncurrent liabilities, period increase (decrease)   0          
Total liabilities assumed, period increase (decrease)   (20)          
Identifiable net assets acquired, period increase (decrease)   $ 0          
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Ambit and Crius Transactions Unaudited Pro Forma Financial Information) (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Ambit Transaction [Member]    
Pro forma revenues $ 12,931 $ 10,446
Pro forma net income (loss) 949 (95)
Pro forma net income (loss) attributable to Vistra $ 951 $ (93)
Pro forma income (loss) attributable to Vistra per weighted average share of common stock outstanding - basic $ 1.92 $ (0.18)
Pro forma net income (loss) attributable to Vistra per weighted average share of common stock outstanding - diluted $ 1.90 $ (0.18)
Crius Transaction [Member]    
Pro forma revenues $ 12,373 $ 10,379
Pro forma net income (loss) 876 (43)
Pro forma net income (loss) attributable to Vistra $ 878 $ (41)
Pro forma income (loss) attributable to Vistra per weighted average share of common stock outstanding - basic $ 1.78 $ (0.08)
Pro forma net income (loss) attributable to Vistra per weighted average share of common stock outstanding - diluted $ 1.76 $ (0.08)
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Dynegy Merger Transaction) (Details) - $ / shares
12 Months Ended
Apr. 09, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Common stock, par or stated value per share   $ 0.01      
Exchange Ratio 0.652        
Shares issued 94,409,573 1,611,462 2,716,349 97,639,105  
Common stock, shares outstanding 522,932,453 489,305,888 487,698,111 493,215,309 428,398,802
Vistra Corp. [Member]          
Common stock, par or stated value per share $ 0.01        
Dynegy Inc.          
Common stock, par or stated value per share $ 0.01        
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Dynegy Merger Business Combination Narrative) (Details) - Dynegy Merger - USD ($)
$ in Millions
9 Months Ended 12 Months Ended
Apr. 09, 2018
Dec. 31, 2018
Mar. 31, 2019
Dec. 31, 2018
Business Combination, consideration transferred $ 2,273      
Property, plant and equipment, period increase (decrease)     $ 173  
Identifiable intangible assets, period increase (decrease)     (36)  
Goodwill, period increase (decrease)     175  
Accounts receivable, inventory, prepaid expenses and other current assets     (10)  
Accumulated deferred income taxes, asset, period increase (decrease)     127  
Other noncurrent assets, period increase (decrease)     (113)  
Trade accounts payable and other current liabilities, period increase (decrease)     89  
Other noncurrent liabilities, period increase (decrease)     177  
Assets retirement obligations, including amounts due currently, period increase (decrease)     $ 56  
Business Combination, acquisition related costs       $ 25
Business Combination, separately recognized transactions, revenues and gains recognized   $ 3,902    
Business Combination, separately recognized transactions, net gains and losses   $ 224    
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Dynergy Merger Purchase Price Allocation) (Details) - USD ($)
$ / shares in Units, $ in Millions
Apr. 09, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Common stock, shares outstanding 522,932,453 489,305,888 487,698,111 493,215,309 428,398,802
Exchange Ratio 0.652        
Preliminary Purchase Price Allocation [Abstract]          
Goodwill   $ 2,583 $ 2,553 $ 2,068  
Dynegy Merger          
Exchange Ratio 0.652        
Opening price of Vistra common stock on April 9, 2018 $ 19.87        
Purchase price for common stock $ 1,876        
Fair value of equity component of tangible equity units 369        
Fair value of outstanding stock compensation awards attributable to pre-combination service 26        
Fair value of outstanding warrants 2        
Total purchase price 2,273        
Preliminary Purchase Price Allocation [Abstract]          
Cash and cash equivalents 445        
Trade accounts receivables, inventories, prepaid expenses and other current assets 853        
Property, plant and equipment 10,535        
Accumulated deferred income taxes 518        
Identifiable intangible assets 351        
Goodwill 175 $ 175      
Other noncurrent assets 419        
Total assets acquired 13,296        
Trade accounts payable and other current liabilities 733        
Commodity and other derivative contractual assets and liabilities, net 422        
Asset retirement obligations, including amounts due currently 475        
Long-term debt, including amounts due currently 8,919        
Other noncurrent liabilities 469        
Total liabilities assumed 11,018        
Identifiable net assets acquired 2,278        
Noncontrolling interest in subsidiary 5        
Total purchase price $ 2,273        
Dynegy Inc. | Dynegy Merger          
Common stock, shares outstanding 144,800,000        
Vistra Corp. [Member] | Dynegy Merger          
Vistra shares issued for Dynegy shares outstanding (in millions) 94,400,000        
v3.20.4
Acquisitions, Merger Transaction and Business Combination Accounting (Dynegy Merger Unaudited Pro Forma Financial Information) (Details) - Dynegy Merger
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2018
USD ($)
$ / shares
Pro forma revenues $ 10,595
Pro Forma Net loss (268)
Pro Forma Net loss attributable to Vistra $ (265)
Pro forma net loss attributable to Vistra per weighted average share of common stock outstanding - basic | $ / shares $ (0.52)
Pro forma net loss attributable to Vistra per weighted average share of common stock outstanding - diluted | $ / shares $ (0.52)
v3.20.4
Acquisition and Development of Generation Facilities (Texas Segment Solar Generation and Energy Storage Projects) (Details)
$ in Millions
1 Months Ended 20 Months Ended
Oct. 31, 2018
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2020
MW
Sep. 30, 2020
MW
Upton County 2 Solar Facility (Battery Storage Project) [Member] [Member]        
Electricity generation facility capacity     180  
Vistra Corp. [Member] | Upton County 2 Solar Facility (Battery Storage Project) [Member] [Member]        
Battery energy storage system capacity     10  
Payments to acquire productive assets | $   $ 231    
Texas Emissions Reduction Plan, grant awarded | $ $ 1      
Texas Segment [Member] | Vistra Corp. [Member]        
Electricity generation facility capacity       668
Battery energy storage system capacity       260
v3.20.4
Acquisition and Development of Generation Facilities (West Segment Energy Storage Projects) (Details)
$ in Millions
1 Months Ended 12 Months Ended
Jun. 30, 2018
Dec. 31, 2020
USD ($)
MW
Dec. 31, 2019
USD ($)
Sep. 30, 2019
MW
Jun. 30, 2019
MW
Construction work in progress, gross | $   $ 712 $ 220    
Vistra Corp. [Member] | Oakland Power Plant (Battery Storage Project) [Member]          
Battery energy storage system capacity | MW       36.25 20
Vistra Corp. [Member] | Moss Landing Power Plant (Battery Storage Project) [Member] | Moss Landing Battery Energy Storage System Phase I [Member]          
Battery energy storage system capacity | MW   300      
Proposed contract, duration, number of years 20        
Construction work in progress, gross | $   $ 370      
Vistra Corp. [Member] | Moss Landing Power Plant (Battery Storage Project) [Member] | Moss Landing Battery Energy Storage System Phase II [Member]          
Battery energy storage system capacity | MW   100      
Proposed contract, duration, number of years   10      
Construction work in progress, gross | $   $ 29      
v3.20.4
Retirement of Generation Facilities (2020 Announcements) (Details)
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
MW
power_plant
generating_unit
Wharton Power Plant [Member]  
Electric generation facility capacity announced retirement 83
Trinidad Power Plant [Member]  
Electric generation facility capacity announced retirement 244
Wharton Power Plant and Trinidad Power Plant [Member]  
Number of electric generation plants announced retirement | power_plant 2
Electric generation facility capacity announced retirement 327
Baldwin Generating Center [Member]  
Electric generation facility capacity announced retirement 1,185
Coleto Creek Power Station [Member]  
Number of electric generation plants announced retirement | generating_unit 1
Electric generation facility capacity announced retirement 650
Joppa Steam Plant (Coal) [Member]  
Electric generation facility capacity announced retirement 802
Joppa Plant (Natural Gas) [Member]  
Number of electric generation plants announced retirement | power_plant 1
Electric generation facility capacity announced retirement 221
Kincaid Generation [Member]  
Electric generation facility capacity announced retirement 1,108
Miami Fort Power Station [Member]  
Electric generation facility capacity announced retirement 1,020
Newton Power Plant [Member]  
Electric generation facility capacity announced retirement 615
William H. Zimmer Power Station [Member]  
Electric generation facility capacity announced retirement 1,300
Baldwin Generating Center, Coleto Creek Power Station, Joppa Steam Plant (Coal), Joppa Plant (Gas), Kincaid Generation, Miami Fort Power Station, Newton Power Plant and William H. Zimmer Power Station [Member]  
Electric generation facility capacity announced retirement 6,901
Charges associated with retirement of generation facilities | $ $ 43
v3.20.4
Retirement of Generation Facilities (2019 Announcements) (Details)
$ in Millions
1 Months Ended 12 Months Ended
Aug. 31, 2019
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2020
MW
power_plant
Coffeen Power Station, Duck Creek Station, Havana Power Station, Hennepin Power Station [Member]      
Number of electric generation plants retired | power_plant     4
Electricity generation facility capacity retired     2,068
Coffeen Power Station [Member]      
Electricity generation facility capacity retired     915
Duck Creek Station [Member]      
Electricity generation facility capacity retired     425
Havana Power Station [Member]      
Electricity generation facility capacity retired     434
Hennepin Power Station [Member]      
Electricity generation facility capacity retired     294
Edwards Power Station [Member]      
Electric generation facility capacity announced retirement     585
Coffeen Power Station, Duck Creek Station, Havana Power Station, Hennepin Power Station, Edwards Power Station [Member]      
Charges associated with retirement of generation facilities | $   $ 47  
Increase (decrease) in obligation, pension and other postretirement benefits | $ $ 21    
Other comprehensive income (loss), defined benefit plan, gain (loss), reclassification adjustment from AOCI, before tax | $ 18    
Curtailment expense | $ $ 3    
Electricity generation facility capacity retired and announced retirements     2,653
v3.20.4
Retirement of Generation Facilities (2018 Announcements) (Details)
Aug. 31, 2018
MW
May 31, 2018
MW
power_plant
Feb. 28, 2018
MW
Northeastern Power Cogeneration Facility [Member]      
Electricity generation facility capacity retired 51    
Killen Station [Member]      
Electricity generation facility capacity retired   204  
Jointly owned utility plant, proportionate ownership share   33.00%  
J.M. Stuart Station [Member]      
Electricity generation facility capacity retired   679  
Jointly owned utility plant, proportionate ownership share   39.00%  
Killen and J.M. Stuart Stations [Member]      
Electricity generation facility capacity retired   883  
Number of electric generation plants retired | power_plant   2  
Monticello Steam Electric Station [Member]      
Electricity generation facility capacity retired     1,880
Sandow Steam Electric Station Units 4 and 5 [Member]      
Electricity generation facility capacity retired     1,137
Big Brown Steam Electric Station [Member]      
Electricity generation facility capacity retired     1,150
Monticello, Sandow and Big Brown Steam Electric Stations [Member]      
Electricity generation facility capacity retired     4,167
Number of electric generation plants retired     3
v3.20.4
Revenue (Revenue Disaggregated By Major Source) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer $ 10,850 $ 11,547 $ 9,797
Operating revenues 11,443 11,809 9,144
Unrealized mark-to-market net gains (losses) (155) (220) (5)
Retail Energy Charge In ERCOT [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 5,813 4,983 4,426
Retail Energy Charge In Northeast/Midwest [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 2,406 1,818 1,123
Wholesale Generation Revenue From ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 1,383 3,244 3,126
Capacity Revenue from ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 112 378 698
Revenue From Other Wholesale Contracts [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 1,136 1,124 424
Intangible amortization [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues (24) (32) (43)
Hedging and other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 617 294 (610)
Affiliate sales [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 0 0 0
Total other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 593 262 (653)
Consolidation, Eliminations [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Operating revenues (4,895) (3,970) (2,607)
Consolidation, Eliminations [Member] | Retail Energy Charge In ERCOT [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Consolidation, Eliminations [Member] | Retail Energy Charge In Northeast/Midwest [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Consolidation, Eliminations [Member] | Wholesale Generation Revenue From ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Consolidation, Eliminations [Member] | Capacity Revenue from ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Consolidation, Eliminations [Member] | Revenue From Other Wholesale Contracts [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Consolidation, Eliminations [Member] | Intangible amortization [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 0 0 0
Consolidation, Eliminations [Member] | Hedging and other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 0 0 2
Consolidation, Eliminations [Member] | Affiliate sales [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues (4,895) (3,970) (2,609)
Consolidation, Eliminations [Member] | Total other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues (4,895) (3,970) (2,607)
Retail Segment [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 8,219 6,801 5,549
Operating revenues 8,270 6,872 5,597
Retail Segment [Member] | Retail Energy Charge In ERCOT [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 5,813 4,983 4,426
Retail Segment [Member] | Retail Energy Charge In Northeast/Midwest [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 2,406 1,818 1,123
Retail Segment [Member] | Wholesale Generation Revenue From ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Retail Segment [Member] | Capacity Revenue from ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Retail Segment [Member] | Revenue From Other Wholesale Contracts [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Retail Segment [Member] | Intangible amortization [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues (5) (15) (26)
Retail Segment [Member] | Hedging and other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 56 86 74
Retail Segment [Member] | Affiliate sales [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 0 0 0
Retail Segment [Member] | Total other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 51 71 48
Texas Segment [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 701 1,741 1,263
Operating revenues 4,116 3,836 2,497
Texas Segment [Member] | Retail Energy Charge In ERCOT [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Texas Segment [Member] | Retail Energy Charge In Northeast/Midwest [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Texas Segment [Member] | Wholesale Generation Revenue From ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 475 1,477 1,049
Texas Segment [Member] | Capacity Revenue from ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Texas Segment [Member] | Revenue From Other Wholesale Contracts [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 226 264 214
Texas Segment [Member] | Intangible amortization [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 0 0 (1)
Texas Segment [Member] | Hedging and other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 416 (250) (387)
Texas Segment [Member] | Affiliate sales [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 2,999 2,345 1,622
Texas Segment [Member] | Total other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 3,415 2,095 1,234
East Segment [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 926 1,501 1,310
Operating revenues 2,415 2,790 1,895
East Segment [Member] | Retail Energy Charge In ERCOT [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
East Segment [Member] | Retail Energy Charge In Northeast/Midwest [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
East Segment [Member] | Wholesale Generation Revenue From ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 310 629 867
East Segment [Member] | Capacity Revenue from ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer (52) 170 376
East Segment [Member] | Revenue From Other Wholesale Contracts [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 668 702 67
East Segment [Member] | Intangible amortization [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 2 (4) (9)
East Segment [Member] | Hedging and other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues (108) 37 16
East Segment [Member] | Affiliate sales [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 1,595 1,256 578
East Segment [Member] | Total other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 1,489 1,289 585
West Segment [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 178 202 203
Operating revenues 282 338 208
West Segment [Member] | Retail Energy Charge In ERCOT [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
West Segment [Member] | Retail Energy Charge In Northeast/Midwest [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
West Segment [Member] | Wholesale Generation Revenue From ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 124 193 167
West Segment [Member] | Capacity Revenue from ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 30
West Segment [Member] | Revenue From Other Wholesale Contracts [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 54 9 6
West Segment [Member] | Intangible amortization [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 0 4 0
West Segment [Member] | Hedging and other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 101 132 5
West Segment [Member] | Affiliate sales [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 3 0 0
West Segment [Member] | Total other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 104 136 5
Sunset Segment [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 824 1,095 1,220
Operating revenues 1,252 1,602 1,183
Sunset Segment [Member] | Retail Energy Charge In ERCOT [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Sunset Segment [Member] | Retail Energy Charge In Northeast/Midwest [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Sunset Segment [Member] | Wholesale Generation Revenue From ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 473 751 825
Sunset Segment [Member] | Capacity Revenue from ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 164 197 258
Sunset Segment [Member] | Revenue From Other Wholesale Contracts [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 187 147 137
Sunset Segment [Member] | Intangible amortization [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues (21) (17) (7)
Sunset Segment [Member] | Hedging and other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 151 247 (214)
Sunset Segment [Member] | Affiliate sales [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 298 277 184
Sunset Segment [Member] | Total other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 428 507 (37)
Asset Closure Segment [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 2 207 252
Operating revenues 3 341 371
Asset Closure Segment [Member] | Retail Energy Charge In ERCOT [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Asset Closure Segment [Member] | Retail Energy Charge In Northeast/Midwest [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 0 0
Asset Closure Segment [Member] | Wholesale Generation Revenue From ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 1 194 218
Asset Closure Segment [Member] | Capacity Revenue from ISO/RTO [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 0 11 34
Asset Closure Segment [Member] | Revenue From Other Wholesale Contracts [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from contracts with customer 1 2 0
Asset Closure Segment [Member] | Intangible amortization [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 0 0 0
Asset Closure Segment [Member] | Hedging and other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 1 42 (106)
Asset Closure Segment [Member] | Affiliate sales [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 0 92 225
Asset Closure Segment [Member] | Total other revenues [Member]      
Disaggregation of Revenue [Line Items]      
Operating revenues 1 134 119
Operating revenues [Member]      
Disaggregation of Revenue [Line Items]      
Unrealized mark-to-market net gains (losses) $ 164 $ 682 $ (380)
v3.20.4
Revenue (Narrative) (Details)
12 Months Ended
Dec. 31, 2020
Retail Segment [Member] | Minimum  
Revenue from contracts with customers, payment terms, number of days due from invoice date 15 days
Retail Segment [Member] | Maximum  
Revenue from contracts with customers, payment terms, number of days due from invoice date 60 days
Texas, East, West and Sunset Segments  
Revenue from contracts with customers, payment terms, number of days due from invoice date 10 days
v3.20.4
Revenue (Contract and Other Customer Acquisition Costs) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Jan. 01, 2018
Selling, general and administrative expenses [Member]        
Capitalized Contract Cost [Line Items]        
Capitalized contract cost, amortization $ 46 $ 21    
Operating revenues [Member]        
Capitalized Contract Cost [Line Items]        
Capitalized contract cost, amortization 7 9    
Costs To Acquire Residential And Business Retail Customers [Member]        
Capitalized Contract Cost [Line Items]        
Capitalized contract cost, net $ 80 $ 53 $ 38 $ 22
v3.20.4
Revenue (Performance Obligations) (Details)
$ in Millions
Dec. 31, 2020
USD ($)
Revenue, remaining performance obligation, expected timing of satisfaction, start date [Axis]: 2021-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Revenue, remaining performance obligation, amount $ 834
Revenue, remaining performance obligation, expected timing of satisfaction, period 1 year
Revenue, remaining performance obligation, expected timing of satisfaction, start date [Axis]: 2022-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Revenue, remaining performance obligation, amount $ 496
Revenue, remaining performance obligation, expected timing of satisfaction, period 1 year
Revenue, remaining performance obligation, expected timing of satisfaction, start date [Axis]: 2023-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Revenue, remaining performance obligation, amount $ 121
Revenue, remaining performance obligation, expected timing of satisfaction, period 1 year
Revenue, remaining performance obligation, expected timing of satisfaction, start date [Axis]: 2024-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Revenue, remaining performance obligation, amount $ 38
Revenue, remaining performance obligation, expected timing of satisfaction, period 1 year
Revenue, remaining performance obligation, expected timing of satisfaction, start date [Axis]: 2025-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Revenue, remaining performance obligation, amount $ 12
Revenue, remaining performance obligation, expected timing of satisfaction, period 1 year
Revenue, remaining performance obligation, expected timing of satisfaction, start date [Axis]: 2026-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Revenue, remaining performance obligation, amount $ 7
Revenue, remaining performance obligation, expected timing of satisfaction, period 2 years
v3.20.4
Revenue (Accounts Receivable) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Trade accounts receivable - net $ 1,279 $ 1,365
Trade accounts receivable from contracts with customers - net [Member]    
Trade accounts receivable - net 1,169 1,246
Other trade accounts receivables [Member]    
Trade accounts receivable - net $ 110 $ 119
v3.20.4
Goodwill and Identifiable Intangible Assets and Liabilities (Goodwill) (Details) - USD ($)
$ in Millions
12 Months Ended
Nov. 01, 2019
Oct. 03, 2016
Dec. 31, 2020
Dec. 31, 2019
Jul. 15, 2019
Dec. 31, 2018
Apr. 09, 2018
Goodwill [Line Items]              
Goodwill     $ 2,583 $ 2,553   $ 2,068  
Retail Reporting Unit [Member]              
Goodwill [Line Items]              
Goodwill     1,907        
Goodwill, expected tax deductible amount   $ 1,686          
Goodwill, expected tax deductible term   15 years          
Dynegy Merger              
Goodwill [Line Items]              
Goodwill     175       $ 175
Goodwill, purchase accounting adjustments       14      
Goodwill, expected tax deductible amount             $ 0
Dynegy Merger | Retail Reporting Unit [Member]              
Goodwill [Line Items]              
Goodwill     53        
Dynegy Merger | Texas Generation Reporting Unit [Member]              
Goodwill [Line Items]              
Goodwill     122        
Crius Transaction [Member]              
Goodwill [Line Items]              
Goodwill         $ 243    
Goodwill, purchase accounting adjustments     (14)        
Goodwill, acquired during period       257      
Goodwill, expected tax deductible amount         $ 0    
Crius Transaction [Member] | Retail Reporting Unit [Member]              
Goodwill [Line Items]              
Goodwill     243        
Ambit Transaction [Member]              
Goodwill [Line Items]              
Goodwill $ 258            
Goodwill, purchase accounting adjustments     44        
Goodwill, acquired during period       $ 214      
Goodwill, expected tax deductible amount $ 258            
Goodwill, expected tax deductible term 15 years            
Ambit Transaction [Member] | Retail Reporting Unit [Member]              
Goodwill [Line Items]              
Goodwill     $ 258        
v3.20.4
Goodwill and Identifiable Intangible Assets and Liabilities (Identifiable Intangible Assets Reported in the Balance Sheet) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount $ 2,915 $ 2,833
Accumulated Amortization 1,844 1,478
Total identifiable intangible assets subject to amortization, net 1,071 1,355
Total identifiable intangible assets 2,446 2,748
Retail trade names (not subject to amortization) [Member]    
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]    
Gross carrying amount, unamortized intangibles 1,374 1,391
Mineral interests (not currently subject to amortization) [Member]    
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]    
Gross carrying amount, unamortized intangibles 1 2
Retail customer relationship [Member]    
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 2,082 2,078
Accumulated Amortization 1,434 1,151
Total identifiable intangible assets subject to amortization, net 648 927
Software and other technology-related assets [Member]    
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 414 341
Accumulated Amortization 186 125
Total identifiable intangible assets subject to amortization, net 228 216
Retail and wholesale contracts [Member]    
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 272 315
Accumulated Amortization 204 182
Total identifiable intangible assets subject to amortization, net 68 133
Contractual service agreements [Member]    
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 51 59
Accumulated Amortization 1 5
Total identifiable intangible assets subject to amortization, net 50 54
Other identifiable intangible assets [Member]    
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 96 40
Accumulated Amortization 19 15
Total identifiable intangible assets subject to amortization, net $ 77 $ 25
v3.20.4
Goodwill and Identifiable Intangible Assets and Liabilities (Identifiable Intangible Liabilities Reported in Balance Sheet) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Schedule of Finite-Lived Intangible Liabilities [Line Items]    
Finite-lived intangible liabilities, net $ 289 $ 286
Contractual service agreements [Member]    
Schedule of Finite-Lived Intangible Liabilities [Line Items]    
Finite-lived intangible liabilities, net 129 110
Purchase and sale of power and capacity    
Schedule of Finite-Lived Intangible Liabilities [Line Items]    
Finite-lived intangible liabilities, net 87 100
Fuel and transportation purchase contracts    
Schedule of Finite-Lived Intangible Liabilities [Line Items]    
Finite-lived intangible liabilities, net $ 73 $ 76
v3.20.4
Goodwill and Identifiable Intangible Assets and Liabilities (Amortization Expense Related to Identifiable Intangible Assets and Liabilities) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]      
Amortization of intangible assets and liabilities $ 596 $ 507 $ 467
Depreciation and amortization [Member]      
Finite-Lived Intangible Assets [Line Items]      
Amortization of intangible assets and liabilities $ 360 340 370
Retail customer relationship [Member] | Depreciation and amortization [Member]      
Finite-Lived Intangible Assets [Line Items]      
Acquired finite-lived intangible assets and liabilities, weighted average useful life 3 years    
Amortization of intangible assets and liabilities $ 283 275 304
Software and other technology-related assets [Member] | Depreciation and amortization [Member]      
Finite-Lived Intangible Assets [Line Items]      
Acquired finite-lived intangible assets and liabilities, weighted average useful life 4 years    
Amortization of intangible assets and liabilities $ 73 61 62
Retail and wholesale contracts/purchase and sale/fuel and transportation contracts | Operating revenues, fuel, purchased power costs and delivery fees [Member]      
Finite-Lived Intangible Assets [Line Items]      
Acquired finite-lived intangible assets and liabilities, weighted average useful life 3 years    
Amortization of intangible assets and liabilities $ 17 23 43
Other identifiable intangible assets [Member] | Operating revenues, fuel, purchased power costs and delivery fees, depreciation and amortization [Member]      
Finite-Lived Intangible Assets [Line Items]      
Acquired finite-lived intangible assets and liabilities, weighted average useful life 5 years    
Amortization of intangible assets and liabilities $ 223 $ 148 $ 58
v3.20.4
Goodwill and Identifiable Intangible Assets and Liabilities (Estimated Amortization of Identifiable Intangible Assets and Liabilities) (Details)
$ in Millions
Dec. 31, 2020
USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]  
2021 $ 276
2022 183
2023 128
2024 78
2025 $ 54
v3.20.4
Income Taxes (Income Tax Expense (Benefit)) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Current:      
U.S. Federal $ (5) $ (1) $ (13)
State 41 10 30
Total current 36 9 17
Deferred:      
U.S. Federal 171 260 (8)
State 59 21 (54)
Total deferred 230 281 (62)
Income tax expense (benefit) $ 266 $ 290 $ (45)
v3.20.4
Income Taxes (Reconciliation of Income Taxes Computed at the U.S. Federal Statutory Rate to Income Tax Expense (Benefit) Recorded (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Tax Disclosure [Abstract]      
Income (loss) before income taxes $ 890 $ 1,216 $ (101)
Effective tax rate at federal statutory rate 21.00% 21.00% 21.00%
Income taxes at the U.S. federal statutory rate $ 187 $ 255 $ (20)
Nondeductible TRA accretion (7) 5 8
State tax, net of federal benefit 32 48 22
Federal and State return to provision adjustment 13 (17) (12)
Remeasurement of historical Vistra deferred taxes for expanded state footprint 0 0 (54)
Effect of refundable minimum tax credits no longer subject to sequestration 0 0 (15)
Nondeductible compensation 0 3 8
Nondeductible transaction costs 0 2 3
Equity awards 0 (4) (3)
Valuation allowance on state NOLs 41 13 20
Lignite depletion (3) (6) 0
Texas gross margin amended return 0 (3) 0
Other 3 (6) (2)
Income tax expense (benefit) $ 266 $ 290 $ (45)
Effective tax rate 29.90% 23.80% 44.60%
v3.20.4
Income Taxes (Deferred Income Tax Balances) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Noncurrent Deferred Income Tax Assets    
Tax credit carryforwards $ 75 $ 73
Loss carryforwards 953 921
Identifiable intangible assets 293 214
Long-term debt 19 257
Employee benefit obligations 129 112
Commodity contracts and interest rate swaps 96 108
Other 47 43
Total deferred tax assets 1,612 1,728
Noncurrent Deferred Income Tax Liabilities    
Property, plant and equipment 632 554
Total deferred tax liabilities 632 554
Valuation allowance 143 110
Net deferred income tax asset $ 837 $ 1,064
v3.20.4
Income Taxes (Income Tax Narrative) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Net deferred income tax asset $ 837 $ 1,064
Valuation allowance 143 110
Operating loss carryforwards 3,400  
Alternative minimum tax credits 0  
Tax effects of the components included in accumulated other comprehensive loss, deferred tax assets 5 $ 3
Illinois And New York [Member]    
Valuation allowance $ 32  
v3.20.4
Income Taxes (CARES Act) (Details) - Internal Revenue Service (IRS) [Member]
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
Income Tax, alternative minimum tax, post-CARES Act, refunds in 2020, amount $ 64
Payroll Tax, CARES Act, payroll tax deferral 22
Tax Years 2019 and 2020 [Member]  
Income Tax, deduction, post-CARES Act, estimated interest expense deduction, amount 350
Tax Year 2021 [Member]  
Income Tax, deduction, post-CARES Act, estimated interest expense deduction, amount $ 305
v3.20.4
Income Taxes (Liability for Uncertain Tax Positions) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]      
Uncertain tax positions, balance at beginning of period, excluding interest and penalties $ 126 $ 39 $ 0
Additions allocated in the Merger 0 0 39
Additions based on tax positions related to prior years 3 3 0
Reductions based on tax positions related to prior years (90) 0 0
Additions based on tax positions related to the current year 0 87 0
Settlements with taxing authorities 0 (3) 0
Uncertain tax positions, balance at end of period, excluding interest and penalties 39 $ 126 $ 39
Unrecognized tax benefit, decrease resulting from rinal Section 163(j) Regulations $ 87    
v3.20.4
Tax Receivable Agreement Obligation (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Income Tax Disclosure [Abstract]        
Percent of cash tax savings due Tax Receivable Agreement rights holders 85.00%      
Additions (reductions) to Tax Receivable Agreement obligation $ (69) $ (22) $ 14  
Tax receivable agreement obligation $ 450 $ 455 $ 420 $ 357
Effective tax rate at federal statutory rate 21.00% 21.00% 21.00%  
Estimated undiscounted future payments under Tax Receivable Agreement $ 1,400      
Estimated number of years half of undiscounted future payments to be made 15 years      
Estimated future tax payments under Tax Receivables Agreement, approximate amount attributable to next fifteen tax years (percent) 50.00%      
v3.20.4
Tax Receivable Agreement Obligation (Summary of Tax Receivables Agreement Obligation) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Tax Disclosure [Abstract]      
TRA obligation at the beginning of the period $ 455 $ 420 $ 357
Accretion expense 64 59 65
Changes in tax assumptions impacting timing of payments (69) (22) 14
Impacts of Tax Receivable Agreement (5) 37 79
Payments 0 (2) (16)
TRA obligation at the end of the period 450 455 420
Less amounts due currently (3) 0 0
Noncurrent TRA obligation at the end of the period $ 447 $ 455 $ 420
v3.20.4
Earnings Per Share (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Earnings Per Share [Abstract]      
Net income (loss) attributable to Vistra $ 636 $ 928 $ (54)
Weighted average shares of common stock outstanding - basic 488,668,263 494,146,268 504,954,371
Net income (loss) per weighted average share of common stock outstanding - basic $ 1.30 $ 1.88 $ (0.11)
Dilutive securities: Stock-based incentive compensation plan 2,422,205 5,789,223 0
Weighted average shares of common stock outstanding - diluted 491,090,468 499,935,490 504,954,371
Net income (loss) per weighted average share of common stock outstanding - diluted $ 1.30 $ 1.86 $ (0.11)
Antidilutive securities excluded from computation of earnings per share, amount 12,553,414 2,447,850 14,165,813
v3.20.4
Accounts Receivable Financing (Details) - USD ($)
$ in Millions
1 Months Ended
Feb. 28, 2021
Mar. 31, 2021
Feb. 23, 2021
Dec. 31, 2020
Jul. 31, 2020
Dec. 31, 2019
Accounts Receivable Securitization Program, Maximum Borrowing Capacity, July Through August 2020         $ 550  
Accounts Receivable Securitization Program, Maximum Borrowing Capacity, August Through November 2020         625  
Accounts Receivable Securitization Program, Maximum Borrowing Capacity, November through December 2020         550  
Accounts Receivable Securitization Program, Maximum Borrowing Capacity, December 2020 through July 2021         $ 450  
Accounts receivable securitization program       $ 300   $ 450
Accounts receivable securitization program, gross trade accounts receivable held by special purpose subsidiary       735   $ 629
Accounts Receivable Repurchase Facility, maximum borrowing capacity       125    
Accounts Receivable Repurchase Facility, amounts borrowed       $ 0    
Subsequent Event            
Accounts receivable securitization program, maximum borrowing capacity   $ 500        
Accounts receivable securitization program     $ 596      
Accounts receivable securitization program, gross trade accounts receivable held by special purpose subsidiary     $ 774      
Proceeds from (repayments of) accounts receivable Repurchase Facility $ 125          
v3.20.4
Long-Term Debt (Long-Term Debt) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 9,330 $ 10,379
Other long-term debt 126 287
Unamortized debt premiums, discounts and issuance costs (68) (55)
Less amounts due currently (95) (277)
Long-term debt, less amounts due currently 9,235 10,102
Line of Credit [Member] | Vistra Operations Credit Facilities [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently 2,572 2,700
Vistra Operations Senior Secured Notes [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently 3,100 3,100
Vistra Operations Senior Secured Notes [Member] | 3.550% Senior Secured Notes Due 2024 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 1,500 1,500
Stated debt interest rate (percent) 3.55%  
Vistra Operations Senior Secured Notes [Member] | 3.700% Senior Secured Notes Due 2027 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 800 800
Stated debt interest rate (percent) 3.70%  
Vistra Operations Senior Secured Notes [Member] | 4.300% Senior Secured Notes Due 2029 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 800 800
Stated debt interest rate (percent) 4.30%  
Vistra Operations Senior Unsecured Notes [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 3,600 3,600
Vistra Operations Senior Unsecured Notes [Member] | 5.500% Senior Notes Due 2026 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 1,000 1,000
Stated debt interest rate (percent) 5.50%  
Vistra Operations Senior Unsecured Notes [Member] | 5.625% Senior Notes Due 2027 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 1,300 1,300
Stated debt interest rate (percent) 5.625%  
Vistra Operations Senior Unsecured Notes [Member] | 5.000% Senior Notes due 2027 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 1,300 1,300
Stated debt interest rate (percent) 5.00%  
Vistra Senior Unsecured Notes [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 0 747
Vistra Senior Unsecured Notes [Member] | 5.875% Senior Notes Due 2023 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 0 500
Stated debt interest rate (percent) 5.875%  
Vistra Senior Unsecured Notes [Member] | 8.000% Senior Notes Due 2025 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 0 81
Stated debt interest rate (percent) 8.00%  
Vistra Senior Unsecured Notes [Member] | 8.125% Senior Notes Due 2026 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 0 166
Stated debt interest rate (percent) 8.125%  
Secured Debt [Member] | Forward Capacity Agreements [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 45 161
Unsecured Debt [Member] | Equipment Financing Agreements [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently 68 99
Building financing [Member] | 8.82% Building Financing due semiannually through 2022 [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 10 15
Stated debt interest rate (percent) 8.82%  
Other debt [Member] | Other debt [Member]    
Debt Instrument [Line Items]    
Long-term debt, including amounts due currently $ 3 $ 12
v3.20.4
Long-Term Debt (Vistra Operations Credit Facilities) (Details) - USD ($)
1 Months Ended 12 Months Ended
Mar. 31, 2020
Jan. 31, 2020
Nov. 30, 2019
Oct. 31, 2019
Jul. 31, 2019
Jun. 30, 2019
Feb. 28, 2019
Aug. 31, 2018
Jun. 30, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Apr. 09, 2018
Line of Credit Facility [Line Items]                          
Gain (loss) on extinguishment of debt                   $ (17,000,000) $ (21,000,000) $ 27,000,000  
Repayments/repurchases of debt                   1,008,000,000 7,109,000,000 3,075,000,000  
Borrowings under Revolving Credit Facility                   1,075,000,000 650,000,000 0  
Repayments under Revolving Credit Facility                   (1,425,000,000) (300,000,000) 0  
Debt fees and expenses, capitalized as noncurrent asset           $ 2,000,000              
Vistra Senior Unsecured Notes [Member]                          
Line of Credit Facility [Line Items]                          
Gain (loss) on extinguishment of debt           (7,000,000) $ (7,000,000) $ 27,000,000   (11,000,000) (11,000,000) 0  
Repayments of Unsecured Debt           845,000,000 1,193,000,000 1,542,000,000   747,000,000 841,000,000 970,000,000  
Long-term debt                         $ 6,138,000,000
Vistra Senior Unsecured Notes [Member] | 7.625% Senior Notes Due 2024 [Member]                          
Line of Credit Facility [Line Items]                          
Repayments/repurchases of debt         $ 1,000,000                
Repayments of Unsecured Debt     $ 87,000,000 $ 387,000,000   672,000,000 0 26,000,000   $ 0 475,000,000 77,000,000  
Vistra Operations Senior Unsecured Notes [Member]                          
Line of Credit Facility [Line Items]                          
Gain (loss) on extinguishment of debt           2,000,000              
Debt fees and expenses, capitalized as reduction of debt           13,000,000 $ 16,000,000 $ 12,000,000          
Vistra Operations Senior Unsecured Notes [Member] | 7.625% Senior Notes Due 2024 [Member]                          
Line of Credit Facility [Line Items]                          
Repayments/repurchases of debt           87,000,000              
Stated debt interest rate (percent)                   7.625%      
Vistra Operations Company LLC [Member] | Cash Released from Collateral Accounts [Member]                          
Line of Credit Facility [Line Items]                          
Cash Collateral for Borrowed Securities                 $ 500,000,000        
Vistra Operations Company LLC [Member] | Vistra Corp. [Member]                          
Line of Credit Facility [Line Items]                          
Cash dividends paid       425,000,000           $ 1,100,000,000 $ 3,900,000,000 $ 4,700,000,000  
Vistra Operations Company LLC [Member] | Line of Credit [Member]                          
Line of Credit Facility [Line Items]                          
Line of credit facility, maximum borrowing capacity                   5,297,000,000      
Gain (loss) on extinguishment of debt           (4,000,000)              
Debt fees and expenses, total                 42,000,000        
Debt fees and expenses, recorded as interest expense     2,000,000           23,000,000        
Debt fees and expenses, capitalized as reduction of debt                 9,000,000        
Debt fees and expenses, capitalized as noncurrent asset                 10,000,000        
Line of credit facility, borrowings outstanding                   2,572,000,000      
Line of credit facility, letters of credit outstanding                   737,000,000      
Line of credit facility, remaining borrowing capacity                   1,988,000,000      
Vistra Operations Company LLC [Member] | Line of Credit [Member] | Senior Secured Revolving Credit Facility [Member]                          
Line of Credit Facility [Line Items]                          
Line of credit facility, maximum borrowing capacity                   2,725,000,000      
Line of credit facility, increase (decrease), net           225,000,000     1,640,000,000        
Borrowings under Revolving Credit Facility       $ 550,000,000           1,075,000,000.000      
Repayments under Revolving Credit Facility     (200,000,000)             (1,425,000,000)      
Line of credit facility, borrowings outstanding                   0      
Line of credit facility, remaining borrowing capacity                   $ 1,988,000,000      
Debt instrument, basis spread on variable rate                   1.75%      
Vistra Operations Company LLC [Member] | Line of Credit [Member] | Senior Secured Revolving Credit Facility [Member] | Maximum                          
Line of Credit Facility [Line Items]                          
Debt Covenant, outstanding borrowings to outstanding commitments threshold, amount of letters of credit excluded                   $ 300,000,000      
Debt Covenant, outstanding borrowings to outstanding commitments threshold, percent                   30.00%      
Debt Covenant, net first lien debt to EBITDA threshold                   4.25      
Vistra Operations Company LLC [Member] | Line of Credit [Member] | Senior Secured Term Loan B-1 Facility [Member]                          
Line of Credit Facility [Line Items]                          
Repayments/repurchases of debt     1,897,000,000     889,000,000              
Vistra Operations Company LLC [Member] | Line of Credit [Member] | Senior Secured Term Loan B-2 Facility [Member] [Member]                          
Line of Credit Facility [Line Items]                          
Repayments/repurchases of debt           977,000,000              
Vistra Operations Company LLC [Member] | Line of Credit [Member] | Senior Secured Term Loan B-3 Facility [Member]                          
Line of Credit Facility [Line Items]                          
Line of credit facility, maximum borrowing capacity                   $ 2,572,000,000      
Line of credit facility, increase (decrease), net $ (100,000,000)   $ (799,000,000)           2,050,000,000.000        
Debt Instrument, Redemption Price 93.875                        
Gain (loss) on extinguishment of debt $ (6,000,000)                        
Repayments/repurchases of debt           134,000,000              
Line of credit facility, borrowings outstanding                   2,572,000,000      
Line of credit facility, remaining borrowing capacity                   $ 0      
Line of Credit Facility percentage of debt required to be repaid annually   1.00%                      
Debt instrument, basis spread on variable rate                   1.75%      
Line of credit facility, interest rate at period end                   1.90%      
Vistra Operations Company LLC [Member] | Line of Credit [Member] | Senior Secured Revolving Credit Facility Letter of Credit Sub-Facility [Member]                          
Line of Credit Facility [Line Items]                          
Line of credit facility, maximum borrowing capacity                   $ 2,350,000,000      
Line of credit facility, increase (decrease), net           $ 50,000,000     1,585,000,000        
Line of credit facility, letters of credit outstanding                   $ 737,000,000      
Line of credit facility, interest rate at period end                   1.75%      
Vistra Operations Company LLC [Member] | Line of Credit [Member] | Senior Secured Term Loan C Facility [Member]                          
Line of Credit Facility [Line Items]                          
Line of credit facility, increase (decrease), net                 $ (500,000,000)        
v3.20.4
Long-Term Debt (Interest Rate Swaps) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Jun. 30, 2019
Jun. 30, 2018
Long-term debt, percentage bearing variable interest, amount $ 2,300    
Interest Rate Swap, Swapped to Fixed, Effective through July 2023      
Derivative, notional amount $ 3,000    
Interest Rate Swap, Swapped to Fixed, Effective through July 2023 | Minimum      
Effective interest rate, debt based on derivative contracts 3.67%    
Interest Rate Swap, Swapped to Fixed, Effective through July 2023 | Maximum      
Effective interest rate, debt based on derivative contracts 3.91%    
Interest Rate Swap, Swapped to Variable, Effective through July 2023      
Derivative, notional amount $ 700    
Interest Rate Swap, Swapped to Variable, Effective through July 2023 | Minimum      
Effective interest rate, debt based on derivative contracts 3.20%    
Interest Rate Swap, Swapped to Variable, Effective through July 2023 | Maximum      
Effective interest rate, debt based on derivative contracts 3.23%    
Interest Rate Swap, Swapped to Fixed, Legacy Swap Effective through February 2024      
Derivative, notional amount $ 720   $ 1,959
Derivative, notional amount, expired   $ 398  
Derivative, notional amount, terminated   $ 841  
Interest Rate Swap, Swapped to Fixed, Legacy Swap Effective through February 2024 | Minimum      
Effective interest rate, debt based on derivative contracts 3.71%    
Interest Rate Swap, Swapped to Fixed, Legacy Swap Effective through February 2024 | Maximum      
Effective interest rate, debt based on derivative contracts 3.72%    
Interest Rate Swap, Swapped to Variable, Legacy Swap Effective through February 2024      
Derivative, notional amount $ 720    
Interest Rate Swap, Swapped to Variable, Legacy Swap Effective through February 2024 | Minimum      
Effective interest rate, debt based on derivative contracts 3.20%    
Interest Rate Swap, Swapped to Variable, Legacy Swap Effective through February 2024 | Maximum      
Effective interest rate, debt based on derivative contracts 3.20%    
Interest Rate Swap, Swapped to Fixed, Effective From July 2023 to July 2026 [Member]      
Derivative, notional amount $ 3,000    
Interest Rate Swap, Swapped to Fixed, Effective From July 2023 to July 2026 [Member] | Minimum      
Effective interest rate, debt based on derivative contracts 4.72%    
Interest Rate Swap, Swapped to Fixed, Effective From July 2023 to July 2026 [Member] | Maximum      
Effective interest rate, debt based on derivative contracts 4.79%    
Interest Rate Swap, Swapped to Variable, Effective From July 2023 to July 2026      
Derivative, notional amount $ 700    
Interest Rate Swap, Swapped to Variable, Effective From July 2023 to July 2026 | Minimum      
Effective interest rate, debt based on derivative contracts 3.28%    
Interest Rate Swap, Swapped to Variable, Effective From July 2023 to July 2026 | Maximum      
Effective interest rate, debt based on derivative contracts 3.33%    
Interest Rate Swap, Swapped to Variable [Member]      
Derivative, notional amount $ 2,120    
v3.20.4
Long-Term Debt (Secured and Alternate Letter of Credit Facilities) (Details) - Vistra Operations Company LLC [Member] - Letter of Credit [Member]
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
credit_facility
Alternate Letter of Credit Facilities Maturing in December 2020 and December 2021  
Line of Credit Facility [Line Items]  
Letter of credit facility, number of credit facilities | credit_facility 2
Alternate Letter of Credit Facility Maturing in December 2020 [Member]  
Line of Credit Facility [Line Items]  
Letter of credit facility, number of credit facilities | credit_facility 1
Letter of credit facility, maximum borrowing capacity $ 250
Alternate Letter of Credit Facility Maturing in December 2021 [Member]  
Line of Credit Facility [Line Items]  
Letters of credit outstanding, amount 245
Letter of credit facility, maximum borrowing capacity $ 250
Secured Letter of Credit Facilities [Member]  
Line of Credit Facility [Line Items]  
Letter of credit facility, number of credit facilities | credit_facility 4
Letters of credit outstanding, amount $ 303
v3.20.4
Long-Term Debt (Vistra Operations Senior Secured Notes) (Details) - Vistra Operations Senior Secured Notes [Member] - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Nov. 30, 2019
Jun. 30, 2019
Dec. 31, 2019
Dec. 31, 2020
Debt Instrument [Line Items]        
Proceeds from issuance of debt $ 1,100 $ 2,000 $ 3,100  
Proceeds from issuance of senior long-term debt 1,099 1,976    
Debt fees and expenses, capitalized as reduction of debt 10 20    
3.550% Senior Secured Notes Due 2024 [Member]        
Debt Instrument [Line Items]        
Proceeds from issuance of debt 300 1,200    
Stated debt interest rate (percent)       3.55%
3.700% Senior Secured Notes Due 2027 [Member]        
Debt Instrument [Line Items]        
Proceeds from issuance of debt 800 0    
Stated debt interest rate (percent)       3.70%
4.300% Senior Secured Notes Due 2029 [Member]        
Debt Instrument [Line Items]        
Proceeds from issuance of debt $ 0 $ 800    
Stated debt interest rate (percent)       4.30%
v3.20.4
Long-Term Debt (Vistra Operations Senior Unsecured Notes) (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended 24 Months Ended
Jun. 30, 2019
Feb. 28, 2019
Aug. 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2019
Repayments/repurchases of debt       $ 1,008 $ 7,109 $ 3,075  
Gain (loss) on extinguishment of debt       $ (17) $ (21) $ 27  
Vistra Operations Senior Unsecured Notes [Member]              
Proceeds from issuance of debt $ 1,300 $ 1,300 $ 1,000       $ 3,600
Proceeds from issuance of senior long-term debt 1,287 1,287 990        
Debt fees and expenses, capitalized as reduction of debt 13 16 12        
Gain (loss) on extinguishment of debt 2            
Vistra Operations Senior Unsecured Notes [Member] | 5.500% Senior Notes Due 2026 [Member]              
Proceeds from issuance of debt 0 0 1,000        
Stated debt interest rate (percent)       5.50%      
Vistra Operations Senior Unsecured Notes [Member] | 5.625% Senior Notes Due 2027 [Member]              
Proceeds from issuance of debt 0 1,300 0        
Stated debt interest rate (percent)       5.625%      
Vistra Operations Senior Unsecured Notes [Member] | 5.000% Senior Notes due 2027 [Member]              
Proceeds from issuance of debt 1,300 0 $ 0        
Stated debt interest rate (percent)       5.00%      
Vistra Operations Senior Unsecured Notes [Member] | 7.375% Senior Notes Due 2022 [Member]              
Stated debt interest rate (percent)       7.375%      
Repayments/repurchases of debt 306 35          
Vistra Operations Senior Unsecured Notes [Member] | 8.034% Senior Notes Due 2024 [Member]              
Stated debt interest rate (percent)       8.034%      
Repayments/repurchases of debt   $ 25          
Vistra Operations Senior Unsecured Notes [Member] | 7.625% Senior Notes Due 2024 [Member]              
Stated debt interest rate (percent)       7.625%      
Repayments/repurchases of debt $ 87            
v3.20.4
Long-Term Debt (Bond Repurchase Program) (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended 24 Months Ended 30 Months Ended
Jul. 31, 2020
Jun. 30, 2020
Mar. 31, 2020
Jan. 31, 2020
Nov. 30, 2019
Jun. 30, 2019
Feb. 28, 2019
Aug. 31, 2018
Jun. 30, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2019
Jun. 30, 2020
Debt Instrument [Line Items]                            
Repayments/repurchases of debt                   $ 1,008 $ 7,109 $ 3,075    
Vistra Senior Unsecured Notes [Member]                            
Debt Instrument [Line Items]                            
Repayments of Unsecured Debt           $ 845 $ 1,193 $ 1,542   747 841 970    
Bond Repurchase Program Authorized November 2018 | Vistra Senior Unsecured Notes [Member]                            
Debt Instrument [Line Items]                            
Bond Repurchase Program, authorized amount                     200   $ 200  
Repayments/repurchases of debt                         $ 119  
Bond Repurchase Program Authorized July 2019 [Member]                            
Debt Instrument [Line Items]                            
Bond Repurchase Program, authorized amount   $ 1,000               1,000       $ 1,000
Repayments/repurchases of debt                           684
Bond Repurchase Program, Remaining Capacity   316                       $ 316
Bond Repurchase Program Authorized April 2020 [Member]                            
Debt Instrument [Line Items]                            
Bond Repurchase Program, authorized amount                   1,000        
Repayments/repurchases of debt                   666        
Senior Secured Term Loan B-3 Facility [Member] | Line of Credit [Member] | Vistra Operations Company LLC [Member]                            
Debt Instrument [Line Items]                            
Repayments/repurchases of debt           134                
Line of credit facility, increase (decrease), net     $ (100)   $ (799)       $ 2,050          
8.000% Senior Notes Due 2025 [Member] | Vistra Senior Unsecured Notes [Member]                            
Debt Instrument [Line Items]                            
Repayments of Unsecured Debt       $ 81   0 0 669   $ 81 0 0    
Stated debt interest rate (percent)                   8.00%        
5.875% Senior Notes Due 2023 [Member] | Vistra Senior Unsecured Notes [Member]                            
Debt Instrument [Line Items]                            
Repayments of Unsecured Debt   $ 500       0 0 0   $ 500 0 0    
Stated debt interest rate (percent)                   5.875%        
8.125% Senior Notes Due 2026 [Member] | Vistra Senior Unsecured Notes [Member]                            
Debt Instrument [Line Items]                            
Repayments of Unsecured Debt $ 166         $ 0 $ 0 $ 684   $ 166 $ 0 $ 0    
Stated debt interest rate (percent)                   8.125%        
v3.20.4
Long-Term Debt (Vistra Corp. Senior Unsecured Notes) (Details) - USD ($)
1 Months Ended 12 Months Ended
Jul. 31, 2020
Jun. 30, 2020
Jan. 31, 2020
Nov. 30, 2019
Oct. 31, 2019
Jul. 31, 2019
Jun. 30, 2019
Feb. 28, 2019
Aug. 31, 2018
May 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Apr. 09, 2018
Gain (loss) on extinguishment of debt                     $ (17,000,000) $ (21,000,000) $ 27,000,000  
Repayments/repurchases of debt                     1,008,000,000 7,109,000,000 3,075,000,000  
Vistra Senior Unsecured Notes [Member]                            
Long-term debt                           $ 6,138,000,000
Repayments of Unsecured Debt             $ 845,000,000 $ 1,193,000,000 $ 1,542,000,000   747,000,000 841,000,000 970,000,000  
Gain (loss) on extinguishment of debt             (7,000,000) (7,000,000) 27,000,000   (11,000,000) (11,000,000) 0  
Vistra Senior Unsecured Notes [Member] | 6.75% Senior Notes Due 2019 [Member]                            
Repayments of Unsecured Debt             0 0 0 $ 850,000,000 0 0 850,000,000  
Stated debt interest rate (percent)                           6.75%
Debt instrument, redemption price, percentage                   101.688%        
Debt fees and expenses, recorded as interest expense                   $ 14,000,000        
Vistra Senior Unsecured Notes [Member] | 7.375% Senior Notes Due 2022 [Member]                            
Repayments of Unsecured Debt       $ 341,000,000     173,000,000 1,193,000,000 0   0 341,000,000 43,000,000  
Vistra Senior Unsecured Notes [Member] | 5.875% Senior Notes Due 2023 [Member]                            
Repayments of Unsecured Debt   $ 500,000,000         0 0 0   $ 500,000,000 0 0  
Stated debt interest rate (percent)                     5.875%      
Debt instrument, redemption price, percentage   100.979%                        
Vistra Senior Unsecured Notes [Member] | 7.625% Senior Notes Due 2024 [Member]                            
Repayments of Unsecured Debt       $ 87,000,000 $ 387,000,000   672,000,000 0 26,000,000   $ 0 475,000,000 77,000,000  
Debt instrument, redemption price, percentage       103.80%                    
Repayments/repurchases of debt           $ 1,000,000                
Vistra Senior Unsecured Notes [Member] | 8.034% Senior Notes Due 2024 [Member]                            
Repayments of Unsecured Debt       $ 25,000,000     0 0 163,000,000   0 25,000,000 0  
Vistra Senior Unsecured Notes [Member] | 8.000% Senior Notes Due 2025 [Member]                            
Repayments of Unsecured Debt     $ 81,000,000       0 0 669,000,000   $ 81,000,000 0 0  
Stated debt interest rate (percent)                     8.00%      
Debt instrument, redemption price, percentage     104.00%                      
Vistra Senior Unsecured Notes [Member] | 8.125% Senior Notes Due 2026 [Member]                            
Repayments of Unsecured Debt $ 166,000,000           0 0 $ 684,000,000   $ 166,000,000 $ 0 $ 0  
Stated debt interest rate (percent)                     8.125%      
Debt instrument, redemption price, percentage 104.063%                          
Vistra Operations Senior Unsecured Notes [Member]                            
Gain (loss) on extinguishment of debt             2,000,000              
Vistra Operations Senior Unsecured Notes [Member] | 7.375% Senior Notes Due 2022 [Member]                            
Stated debt interest rate (percent)                     7.375%      
Repayments/repurchases of debt             306,000,000 35,000,000            
Vistra Operations Senior Unsecured Notes [Member] | 7.625% Senior Notes Due 2024 [Member]                            
Stated debt interest rate (percent)                     7.625%      
Repayments/repurchases of debt             $ 87,000,000              
Vistra Operations Senior Unsecured Notes [Member] | 8.034% Senior Notes Due 2024 [Member]                            
Stated debt interest rate (percent)                     8.034%      
Repayments/repurchases of debt               $ 25,000,000            
v3.20.4
Long-Term Debt (Other Long-Term Debt) (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Nov. 30, 2019
Oct. 31, 2019
Jul. 31, 2019
Jun. 30, 2018
Apr. 30, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Jul. 15, 2019
Jul. 01, 2019
Apr. 09, 2018
Long-term debt, including amounts due currently           $ 9,330 $ 10,379        
Repayments/repurchases of debt           1,008 7,109 $ 3,075      
Amortizing Notes Due 2019 (Tangible Equity Units) [Member] | 7% Amortizating Notes due 2019 [Member]                      
Stated debt interest rate (percent)                   7.00% 7.00%
Secured Debt [Member] | Forward Capacity Agreements [Member]                      
Long-term debt, including amounts due currently           $ 45 $ 161        
Debt instrument, interest rate, effective percentage           1.14%          
Secured Debt [Member] | Forward Capacity Agreements [Member] | PJM Capacity Sold For Planning Years 2020-2021 [Member]                      
Long-term debt, including amounts due currently           $ 45          
Mandatorily Redeemable Preferred Stock [Member] | Mandatorily redeemable preferred stock [Member]                      
Repayments/repurchases of debt   $ 70                  
Line of Credit [Member] | Revolving Credit Facility [Member]                      
Long-term debt, including amounts due currently                 $ 88    
Repayments/repurchases of debt     $ 88                
Line of Credit [Member] | Letter Of Credit Facility [Member]                      
Line of credit facility, letters of credit outstanding                 9    
Promissory Notes [Member] | 9.5% Promissory Notes Due 2025 [Member]                      
Stated debt interest rate (percent)           9.50%          
Long-term debt, including amounts due currently                 44    
Repayments/repurchases of debt $ 38                    
Borrowings offset under legacy indemnification obligations of the holders 2                    
Term Loan [Member] | 2% Term Loan Due February 2027 [Member]                      
Stated debt interest rate (percent)           2.00%          
Long-term debt, including amounts due currently                 8    
Repayments/repurchases of debt $ 8                    
Dynegy Inc.                      
Long-term debt, including amounts due currently                     $ 3,563
Dynegy Inc. | Line of Credit [Member] | Senior Secured Revolving Credit Facility [Member]                      
Line of credit facility, letters of credit outstanding                     656
Dynegy Inc. | Borrowings [Member] | Senior Secured Revolving Credit Facility [Member]                      
Line of credit facility, borrowings outstanding                     0
Dynegy Inc. | Line of Credit [Member] | Senior Secured Revolving Credit Facility [Member]                      
Line of credit facility, increase (decrease), other, net         $ (70)            
Dynegy Inc. | Revolving Credit Facility [Member]                      
Line of credit facility, maximum borrowing capacity                     1,545
Dynegy Inc. | Senior Secured Term Loan [Member]                      
Long-term debt, including amounts due currently                     $ 2,018
Repayments/repurchases of debt       $ 2,018              
Subsidiaries Of Crius Energy Trust Purchased By Vistra Energy [Member] | Line of Credit [Member]                      
Long-term debt                 $ 140    
v3.20.4
Long-Term Debt (Maturities) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Debt Disclosure [Abstract]    
2021 $ 98  
2022 44  
2023 40  
2024 1,540  
2025 2,470  
Thereafter 5,206  
Unamortized premiums, discounts and debt issuance costs (68)  
Long-term debt, including amounts due currently $ 9,330 $ 10,379
v3.20.4
Leases (Narrative) (Details)
12 Months Ended
Dec. 31, 2020
USD ($)
Lessee, Lease, Description [Line Items]  
Lease renewal term, lessee 15 years
Lease not yet commenced, lessee $ 7,000,000
Minimum  
Lessee, Lease, Description [Line Items]  
Remaining lease term 1 year
Maximum  
Lessee, Lease, Description [Line Items]  
Remaining lease term 37 years
v3.20.4
Leases (Lease Cost) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Leases [Abstract]    
Operating lease cost $ 14 $ 14
Finance Lease:    
Finance lease right-of-use asset amortization 7 4
Interest on lease liabilities 7 4
Total finance lease cost 14 8
Variable lease cost 29 26
Short-term lease cost 31 19
Sublease income (8) (8)
Net lease cost $ 80 $ 59
v3.20.4
Leases (Balance Sheet Information) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Lease assets:    
Operating lease right-of-use asset $ 45 $ 44
Finance lease right-of-use asset (net of accumulated depreciation) 182 59
Total lease right-of-use asset 227 103
Current lease liabilities:    
Operating lease liabilities 8 14
Finance lease liabilities 8 8
Total current lease liabilities 16 22
Noncurrent lease liabilities:    
Operating lease liabilities 40 41
Finance lease liabilities 206 78
Total noncuurrent lease liabilities 246 119
Present value of lease liabilities (Total) $ 262 $ 141
v3.20.4
Leases (Cash Flow and Other Information) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:    
Operating cash flows from operating leases $ 17 $ 17
Operating cash flows from finance leases 5 4
Finance cash flows from finance leases 10 4
Non-cash disclosure upon commencement of new lease:    
Right-of-use assets obtained in exchange for new operating lease liabilities 14 95
Right-of-use assets obtained in exchange for new finance lease liabilities 108 13
Non-cash disclosure upon modification of existing lease:    
Modification of operating lease right-of-use assets (1) (41)
Modification of finance lease right-of-use assets $ 23 $ 50
v3.20.4
Leases (Weighted Average Remaining Lease Term) (Details)
Dec. 31, 2020
Dec. 31, 2019
Weighted average remaining lease term:    
Operating lease 12 years 3 months 18 days 7 years 6 months
Finance lease 24 years 2 months 12 days 16 years 2 months 12 days
Weighted average discount rate:    
Operating lease 5.80% 5.34%
Finance lease 4.92% 5.84%
v3.20.4
Leases (Maturity of Lease Liabilities) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Operating lease    
2021 (Operating) $ 11  
2022 (Operating) 8  
2023 (Operating) 9  
2024 (Operating) 5  
2025 (Operating) 3  
Thereafter (Operating) 41  
Total lease payments (Operating) 77  
Less: Interest (Operating) (29)  
Present value of lease liabilities 48  
Finance lease    
2021 (Finance) 14  
2022 (Finance) 20  
2023 (Finance) 19  
2024 (Finance) 19  
2025 (Finance) 19  
Thereafter (Finance) 385  
Total lease payments (Finance) 476  
Less: Interest (Finance) (262)  
Present value of lease liabilities 214  
Total lease    
2021 (Total) 25  
2022 (Total) 28  
2023 (Total) 28  
2024 (Total) 24  
2025 (Total) 22  
Thereafter (Total) 426  
Total lease payments (Total) 553  
Less: Interest (Total) (291)  
Present value of lease liabilities $ 262 $ 141
v3.20.4
Commitments and Contingencies (Contractual Commitments) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Long-term Purchase Commitment [Line Items]      
Rent expense $ 111 $ 89 $ 74
Long-term Service and Maintenance Contracts [Member]      
Long-term Purchase Commitment [Line Items]      
2021 165    
2022 186    
2023 137    
2024 142    
2025 170    
Thereafter 1,824    
Total 2,624    
Coal Purchase and Transportation Agreements [Member]      
Long-term Purchase Commitment [Line Items]      
2021 516    
2022 47    
2023 34    
2024 36    
2025 37    
Thereafter 79    
Total 749    
Contractual obligations expenditures 845 $ 1,092 $ 955
Pipeline Transportation and Storage Reservation Fees [Member]      
Long-term Purchase Commitment [Line Items]      
2021 100    
2022 73    
2023 49    
2024 36    
2025 30    
Thereafter 111    
Total 399    
Nuclear Fuel Contracts [Member]      
Long-term Purchase Commitment [Line Items]      
2021 92    
2022 43    
2023 57    
2024 40    
2025 36    
Thereafter 107    
Total 375    
Other Contracts [Member]      
Long-term Purchase Commitment [Line Items]      
2021 256    
2022 49    
2023 29    
2024 24    
2025 11    
Thereafter 80    
Total $ 449    
v3.20.4
Commitments and Contingencies (Guarantees, Letters of Credit and Surety Bonds) (Details) - Vistra Operations Company LLC [Member]
$ in Millions
Dec. 31, 2020
USD ($)
Letters of Credit [Member]  
Commitments and Contingencies [Line Items]  
Letters of credit outstanding, amount $ 1,286
Letters of Credit [Member] | Support commodity risk management and trading margin requirements including over the counter hedging transactions and collateral postings with ISOs or RTOs [Member]  
Commitments and Contingencies [Line Items]  
Letters of credit outstanding, amount 878
Letters of Credit [Member] | Support battery and solar development projects [Member]  
Commitments and Contingencies [Line Items]  
Letters of credit outstanding, amount 190
Letters of Credit [Member] | Support executory contracts and insurance agreements [Member]  
Commitments and Contingencies [Line Items]  
Letters of credit outstanding, amount 34
Letters of Credit [Member] | Support Retail Electric Provider's financial requirements with the Public Utility Commission of Texas [Member]  
Commitments and Contingencies [Line Items]  
Letters of credit outstanding, amount 102
Letters of Credit [Member] | Miscellaneous credit support requirements [Member]  
Commitments and Contingencies [Line Items]  
Letters of credit outstanding, amount 82
Surety Bonds [Member]  
Commitments and Contingencies [Line Items]  
Surety Bonds $ 100
v3.20.4
Commitments and Contingencies (Litigation, Regulatory and Environmental Proceedings) (Details)
12 Months Ended
Dec. 31, 2020
MW
Vermillion Facility Old East And North Sites [Member]  
Commitments and Contingencies [Line Items]  
Site contingency, number of sites with regulatory violations 2
Gas Index Pricing Litigation [Member] | Wisconsin  
Commitments and Contingencies [Line Items]  
Loss contingency, pending claims, number 2
Gas Index Pricing Litigation [Member] | Kansas  
Commitments and Contingencies [Line Items]  
Loss contingency, pending claims, number 1
ME2C Patent Dispute [Member]  
Commitments and Contingencies [Line Items]  
Loss contingency, patents allegedly infringed, number 5
MISO 2015-2016 Planning Resource Auction [Member]  
Commitments and Contingencies [Line Items]  
Loss contingency, pending claims, number 3
Pending Litigation [Member] | MISO 2015-2016 Planning Resource Auction [Member]  
Commitments and Contingencies [Line Items]  
Loss contingency, pending claims, number 1
United States Environmental Protection Agency [Member]  
Commitments and Contingencies [Line Items]  
Clean Air Act, Regional Haze Program, Best Available Retrofit Technology Alternative, sulfur dioxide emissions, number of units in Texas subject to rule, total 39
Startup, shutdown and malfunction events, number of states impacted by final rule 36
Illinois Environmental Protection Agency [Member]  
Commitments and Contingencies [Line Items]  
Illinois Multi-Pollutant Standards, proposed rule reduction in allowable annual emissions of nitrogen-oxide 42.00%
Illinois Multi-Pollutant Standards, proposed rule reduction in allowable annual emissions of sulfur dioxide 48.00%
Illinois Multi-Pollutant Standards, additional reduction in emissions, MW 2,000
v3.20.4
Commitments and Contingencies (Nuclear Insurance) (Details)
$ in Millions
Dec. 31, 2020
USD ($)
Commitments and Contingencies [Line Items]  
Secondary Financial Protection Pool, maximum assessment paid per operating licensed reactor in the event of any single nuclear liability loss $ 137.6
Secondary Financial Protection Pool, maximum assessment paid per operating licensed reactor in the event of any single nuclear liability loss, annual 20.5
Nuclear Decontamination And Property Insurance, maximum coverage 2,250.0
Non-Nuclear Property Damage Insurance, maximum coverage 1,000.0
Non-Nuclear Property Damage Insurance, deductible per accident, general 5.0
Non-Nuclear Property Damage Insurance, deductible per incident, natural hazard 9.5
Accidental Outage Insurance, coverage for obtaining replacement energy after 12 week waiting period, maximum weekly coverage, first 52 weeks 4.5
Accidental Outage Insurance, coverage for obtaining replacement energy after 12 week waiting period, maximum weekly payments, remaining 71 weeks 3.6
Accidental Outage Insurance, coverage for obtaining replacement energy, coverage limit for non-nuclear accidents 328.0
Accidental Outage Insurance, coverage for obtaining replacement energy, coverage limit for nuclear accidents $ 490.0
Accidental Outage Insurance, coverage for obtaining replacement energy after 12 week waiting period, maximum percent of coverage if both units out of service 80.00%
Vistra Corp. [Member]  
Commitments and Contingencies [Line Items]  
Secondary Financial Protection Pool, maximum assessment paid in the event of any single nuclear liability loss $ 275.0
Secondary Financial Protection Pool, maximum assessment paid in the event of any single nuclear liability loss, annual 41.0
Section 170 (Price-Anderson) Of The Atomic Energy Act [Member]  
Commitments and Contingencies [Line Items]  
Nuclear Insurance, annual coverage limit 13,800.0
Secondary Financial Protection Pool, maximum single nuclear liability loss triggering assessment 450.0
United States Nuclear Regulatory Commission [Member]  
Commitments and Contingencies [Line Items]  
Required Nuclear Decontamination And Property Damage Insurance, maximum coverage $ 1,060.0
v3.20.4
Equity (Equity Issuances and Repurchases) (Details) - shares
12 Months Ended 36 Months Ended
Apr. 09, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2020
Stockholders' Equity Attributable to Parent [Abstract]          
Shares issued at beginning of period   528,741,335 526,031,092 428,398,802 428,398,802
Shares issued 94,409,573 1,611,462 2,716,349 97,639,105  
Shares retired   (3,685) (6,106) (6,815)  
Shares repurchased     0 0  
Shares issued at end of period   530,349,112 528,741,335 526,031,092 530,349,112
Treasury shares at beginning of period   (41,043,224) (32,815,783) 0 0
Shares issued   0 18,773,958 0  
Shares retired   0 0 0  
Shares repurchased     (27,001,399) (32,815,783)  
Treasury shares at end of period   (41,043,224) (41,043,224) (32,815,783) (41,043,224)
Shares outstanding at beginning of period   487,698,111 493,215,309 428,398,802 428,398,802
Shares issued   1,611,462 21,490,307 97,639,105  
Shares retired   (3,685) (6,106) (6,815)  
Shares repurchased     (27,001,399) (32,815,783)  
Shares outstanding at end of period 522,932,453 489,305,888 487,698,111 493,215,309 489,305,888
v3.20.4
Equity (Share Repurchase Program) (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended 36 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2020
Jan. 01, 2021
Stock Repurchase Program, authorized amount $ 1,750     $ 1,750  
Shares repurchased   27,001,399 32,815,783    
Stock repurchaes   $ 641 $ 778    
Share Repurchase Program Approved by Board of Directors in June 2018 [Member]          
Stock Repurchase Program, authorized amount $ 500     $ 500  
Shares repurchased 0 0 21,421,925 21,421,925  
Treasury stock acquired, average cost per share $ 0 $ 0 $ 23.36 $ 23.36  
Stock repurchaes $ 0 $ 0 $ 500 $ 500  
Share Repurchase Program Approved by Board of Directors in November 2018 [Member]          
Stock Repurchase Program, authorized amount $ 1,250     $ 1,250  
Shares repurchased 0 26,322,166 12,073,091 38,395,257  
Treasury stock acquired, average cost per share $ 0 $ 24.34 $ 22.99 $ 23.91  
Stock repurchaes $ 0 $ 640 $ 278 $ 918  
Share Repurchase Program Approved by Board of Directors in September 2020 [Member] | Subsequent Event          
Stock Repurchase Program, authorized amount         $ 1,500
v3.20.4
Equity (Dividends and Dividend Restrictions) (Details) - USD ($)
$ / shares in Units, $ in Millions
1 Months Ended 12 Months Ended
Feb. 28, 2021
Dec. 31, 2020
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2020
Dec. 31, 2019
Oct. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dividends per share, paid   $ 0.135 $ 0.135 $ 0.135 $ 0.135 $ 0.125   $ 0.125 $ 0.125 $ 0.125      
Maximum allowable distribution to parent company by consolidated subsidiary without consent   $ 6,700                 $ 6,700    
Parent Company [Member]                          
Cash dividends paid                     1,100 $ 3,900 $ 4,700
Amount of restricted net assets   1,200                 1,200    
Vistra Operations Company LLC [Member] | Vistra Corp. [Member]                          
Maximum allowable distribution to parent company by consolidated subsidiary without consent   $ 6,700                 6,700    
Cash dividends paid             $ 425       $ 1,100 $ 3,900 $ 4,700
Subsequent Event                          
Dividends per share, declared $ 0.15                        
v3.20.4
Equity (Other Equity) (Details)
1 Months Ended 12 Months Ended
Apr. 09, 2018
USD ($)
equity_unit
shares
Jul. 31, 2019
USD ($)
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Jul. 01, 2019
Change in funded status of pension and other postretirement employee benefit liability     $ 23,000,000 $ 11,000,000 $ 9,000,000  
Reclassification from accumulated other comprehensive income, current period, net of tax     $ (5,000,000) (3,000,000) $ (3,000,000)  
Class of warrant or right, outstanding | shares     9,000,000      
Class of warrant or right, exercise price of warrants or rights | $ / shares     $ 35.00      
Tangible Equity Units, number Of units issued | shares 4,600,000          
Tangible Equity Units, unit price | equity_unit 100.00          
Prepaid Stock Purchase Contract, settlement rate per tangible equity unit   $ 22.5954        
Long-term debt, less amounts due currently     $ 9,235,000,000 $ 10,102,000,000    
Prepaid Stock Purchase Contract, number of common shares issued upon settlement | shares   18,800,000        
Maximum            
Prepaid Stock Purchase Contract, number of common shares per Tangible Equity Unit | shares   4.0813        
Amortizing Notes Due 2019 (Tangible Equity Units) [Member]            
Debt Instrument, periodic payment $ 1.75          
Amortizing Notes Due 2019 (Tangible Equity Units) [Member] | 7% Amortizating Notes due 2019 [Member]            
Stated debt interest rate (percent) 7.00%         7.00%
Long-term debt, less amounts due currently $ 38,000,000          
v3.20.4
Fair Value Measurements (Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Assets:    
Nuclear decommissioning trust $ 1,674 $ 1,451
Equity securities [Member]    
Assets:    
Nuclear decommissioning trust 1,056 930
Debt securities [Member]    
Assets:    
Nuclear decommissioning trust 618 521
Fair Value, Recurring [Member]    
Assets:    
Sub-total 76 11
Liabilities:    
Total liabilities 76 11
Fair Value, Recurring [Member] | Total [Member]    
Assets:    
Sub-total 2,247 2,554
Total assets 2,680 2,920
Liabilities:    
Total liabilities 1,413 1,925
Fair Value, Recurring [Member] | Equity securities [Member]    
Assets:    
Assets measured at net asset value 433 366
Fair Value, Recurring [Member] | Equity securities [Member] | Total [Member]    
Assets:    
Nuclear decommissioning trust 623 564
Fair Value, Recurring [Member] | Debt securities [Member] | Total [Member]    
Assets:    
Nuclear decommissioning trust 618 521
Fair Value, Recurring [Member] | Commodity contracts [Member]    
Assets:    
Derivative assets 76 11
Liabilities:    
Derivative liabilities 76 11
Fair Value, Recurring [Member] | Commodity contracts [Member] | Total [Member]    
Assets:    
Derivative assets 934 1,469
Liabilities:    
Derivative liabilities 1,009 1,748
Fair Value, Recurring [Member] | Interest rate swap [Member] | Total [Member]    
Assets:    
Derivative assets 72  
Liabilities:    
Derivative liabilities 404 177
Level 1 [Member] | Fair Value, Recurring [Member]    
Assets:    
Sub-total 1,075 1,611
Liabilities:    
Total liabilities 578 985
Level 1 [Member] | Fair Value, Recurring [Member] | Equity securities [Member]    
Assets:    
Nuclear decommissioning trust 623 564
Level 1 [Member] | Fair Value, Recurring [Member] | Commodity contracts [Member]    
Assets:    
Derivative assets 452 1,047
Liabilities:    
Derivative liabilities 578 985
Level 2 [Member] | Fair Value, Recurring [Member]    
Assets:    
Sub-total 891 693
Liabilities:    
Total liabilities 576 616
Level 2 [Member] | Fair Value, Recurring [Member] | Debt securities [Member]    
Assets:    
Nuclear decommissioning trust 618 521
Level 2 [Member] | Fair Value, Recurring [Member] | Commodity contracts [Member]    
Assets:    
Derivative assets 201 172
Liabilities:    
Derivative liabilities 172 439
Level 2 [Member] | Fair Value, Recurring [Member] | Interest rate swap [Member]    
Assets:    
Derivative assets 72  
Liabilities:    
Derivative liabilities 404 177
Level 3 [Member]    
Assets:    
Sub-total 205 239
Liabilities:    
Total liabilities 183 313
Level 3 [Member] | Fair Value, Recurring [Member]    
Assets:    
Sub-total 205 239
Liabilities:    
Total liabilities 183 313
Level 3 [Member] | Fair Value, Recurring [Member] | Commodity contracts [Member]    
Assets:    
Derivative assets 205 239
Liabilities:    
Derivative liabilities $ 183 $ 313
v3.20.4
Fair Value Measurements (Schedule of Fair Value of the Level 3 Assets and Liabilities by Major Contract Type (All Related to Commodity Contracts) and the Significant Unobservable Inputs Used in the Valuations) (Details) - Level 3 [Member] - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Assets $ 205,000,000 $ 239,000,000
Liabilities (183,000,000) (313,000,000)
Derivative Assets (Liabilities), at Fair Value, Net 22,000,000 (74,000,000)
Electricity purchases and sales [Member] | Valuation, Income Approach [Member]    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Assets 61,000,000 64,000,000
Liabilities (90,000,000) (53,000,000)
Derivative Assets (Liabilities), at Fair Value, Net (29,000,000) 11,000,000
Electricity purchases and sales [Member] | Valuation, Income Approach [Member] | Minimum    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Hourly price curve shape (in USD per MWh) 0 0
Fair Value Inputs, Illiquid delivery periods for hub power prices and heat rates (in USD per MWh) 25 20
Electricity purchases and sales [Member] | Valuation, Income Approach [Member] | Maximum    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Hourly price curve shape (in USD per MWh) 85 115
Fair Value Inputs, Illiquid delivery periods for hub power prices and heat rates (in USD per MWh) 125 120
Electricity purchases and sales [Member] | Valuation, Income Approach [Member] | Arithmetic Average    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Hourly price curve shape (in USD per MWh) 43 58
Fair Value Inputs, Illiquid delivery periods for hub power prices and heat rates (in USD per MWh) 75 70
Options [Member] | Option Pricing Model Valuation Technique [Member]    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Assets 38,000,000 38,000,000
Liabilities (56,000,000) (188,000,000)
Derivative Assets (Liabilities), at Fair Value, Net $ (18,000,000) $ (150,000,000)
Options [Member] | Option Pricing Model Valuation Technique [Member] | Minimum    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Gas to power correlation (percent) 30.00% 10.00%
Fair Value Inputs, Power and gas volatility (percent) 5.00% 5.00%
Options [Member] | Option Pricing Model Valuation Technique [Member] | Maximum    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Gas to power correlation (percent) 100.00% 100.00%
Fair Value Inputs, Power and gas volatility (percent) 665.00% 440.00%
Options [Member] | Option Pricing Model Valuation Technique [Member] | Arithmetic Average    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Gas to power correlation (percent) 64.00% 55.00%
Fair Value Inputs, Power and gas volatility (percent) 336.00% 223.00%
Financial Transmission Rights [Member] | Market Approach [Member]    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Assets $ 92,000,000 $ 120,000,000
Liabilities (16,000,000) (26,000,000)
Derivative Assets (Liabilities), at Fair Value, Net 76,000,000 94,000,000
Financial Transmission Rights [Member] | Market Approach [Member] | Minimum    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Illiquid price differences between settlement points (in USD per MWh) (5) (10)
Financial Transmission Rights [Member] | Market Approach [Member] | Maximum    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Illiquid price differences between settlement points (in USD per MWh) 50 40
Financial Transmission Rights [Member] | Market Approach [Member] | Arithmetic Average    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Fair Value Inputs, Illiquid price differences between settlement points (in USD per MWh) 22 15
Other [Member]    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Assets 14,000,000 17,000,000
Liabilities (21,000,000) (46,000,000)
Derivative Assets (Liabilities), at Fair Value, Net $ (7,000,000) $ (29,000,000)
v3.20.4
Fair Value Measurements (Schedule of Changes in Fair Value of the Level 3 Assets and Liabilities (All Related to Commodity Contracts)) (Details) - Level 3 [Member] - Commodity Contract [Member] - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]      
Net liability balance at beginning of period $ (74) $ (135) $ (53)
Total unrealized valuation gains (losses) (5) 8 (363)
Purchases, issuances and settlements:      
Purchases 164 176 146
Issuances (28) (81) (41)
Settlements (90) (64) 76
Transfers into Level 3 (2) 10 4
Transfers out of Level 3 57 12 133
Net change 96 61 (82)
Net asset (liability) balance at end of period 22 (74) (135)
Unrealized valuation gains (losses) relating to instruments held at end of period 18 (61) (174)
Dynegy Inc.      
Purchases, issuances and settlements:      
Net liabilities assumed in connection with the Merger $ 0 $ 0 $ (37)
v3.20.4
Commodity And Other Derivative Contractual Assets And Liabilities (Financial Statement Effects of Derivatives) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross asset $ 930 $ 1,458
Derivative liabilities, fair value, gross liability (1,337) (1,914)
Derivative, fair value, net (407) (456)
Current assets [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets and liability, fair value, gross assets 748 1,333
Noncurrent assets [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets and liability, fair value, gross assets 258 136
Current liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets and liability, fair value, gross liability (789) (1,529)
Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets and liability, fair value, gross liability (624) (396)
Commodity contracts [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross asset 858 1,458
Derivative liabilities, fair value, gross liability (933) (1,737)
Derivative asset, fair value, net 858 1,458
Derivative liabilities, fair value, net (933) (1,737)
Commodity contracts [Member] | Current assets [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross asset 665 1,323
Derivative liabilities, fair value, gross asset 64 10
Commodity contracts [Member] | Noncurrent assets [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross asset 197 136
Derivative liabilities, fair value, gross asset 8 0
Commodity contracts [Member] | Current liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross liability (1) (1)
Derivative liabilities, fair value, gross liability (717) (1,510)
Commodity contracts [Member] | Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross liability (3) 0
Derivative liabilities, fair value, gross liability (288) (237)
Interest rate swap [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross asset 72 0
Derivative liabilities, fair value, gross liability (404) (177)
Derivative asset, fair value, net 72 0
Derivative liabilities, fair value, net (404) (177)
Interest rate swap [Member] | Current assets [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross asset 19 0
Derivative liabilities, fair value, gross asset 0 0
Interest rate swap [Member] | Noncurrent assets [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross asset 53 0
Derivative liabilities, fair value, gross asset 0 0
Interest rate swap [Member] | Current liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross liability 0 0
Derivative liabilities, fair value, gross liability (71) (18)
Interest rate swap [Member] | Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value, gross liability 0 0
Derivative liabilities, fair value, gross liability $ (333) $ (159)
v3.20.4
Commodity And Other Derivative Contractual Assets And Liabilities (Derivative Consolidated Statements of Operations Presentation) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]      
Net gain (loss) $ 49 $ 121 $ (848)
Operating revenues [Member] | Commodity contracts [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Net gain (loss) 241 339 (855)
Fuel, purchased power costs and delivery fees [Member] | Commodity contracts [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Net gain (loss) 4 (1) 18
Interest expense and related charges [Member] | Interest rate swap [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Net gain (loss) $ (196) $ (217) $ (11)
v3.20.4
Commodity And Other Derivative Contractual Assets And Liabilities (Derivative Assets and Liabilities From Balance Sheet to Net Amounts After Consideration Netting Arrangements with Counterparties and Financial Collateral) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Derivatives, Fair Value [Line Items]    
Derivative assets: amounts presented in balance sheet $ 930 $ 1,458
Derivative assets: offsetting financial instruments (739) (1,113)
Derivative assets: financial collateral (received) pledged (11) 0
Derivative assets: net amounts 180 345
Derivative liabilities: amounts presented in balance sheet (1,337) (1,914)
Derivative liabilities: offsetting financial instruments 739 1,113
Derivative liabilities: financial collateral (received) pledged 138 40
Derivative liabilities: net amounts (460) (761)
Derivative, fair value, net (407) (456)
Derivative (assets) liability, fair value of collateral, net 127 40
Derivative assets (liability), fair value, amount offset against collateral (280) (416)
Commodity contracts [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets: amounts presented in balance sheet 858 1,458
Derivative assets: offsetting financial instruments (667) (1,113)
Derivative assets: financial collateral (received) pledged (11) 0
Derivative assets: net amounts 180 345
Derivative liabilities: amounts presented in balance sheet (933) (1,737)
Derivative liabilities: offsetting financial instruments 667 1,113
Derivative liabilities: financial collateral (received) pledged 138 40
Derivative liabilities: net amounts (128) (584)
Interest rate swap [Member]    
Derivatives, Fair Value [Line Items]    
Derivative assets: amounts presented in balance sheet 72 0
Derivative assets: offsetting financial instruments (72) 0
Derivative assets: financial collateral (received) pledged 0 0
Derivative assets: net amounts 0 0
Derivative liabilities: amounts presented in balance sheet (404) (177)
Derivative liabilities: offsetting financial instruments 72 0
Derivative liabilities: financial collateral (received) pledged 0 0
Derivative liabilities: net amounts $ (332) $ (177)
v3.20.4
Commodity And Other Derivative Contractual Assets And Liabilities (Derivative Volumes) (Details)
number in Millions, gal in Millions, T in Millions, MMBTU in Millions, $ in Millions
Dec. 31, 2020
USD ($)
T
MMBTU
GWh
gal
Dec. 31, 2019
USD ($)
T
gal
GWh
MMBTU
Natural gas (in MMBtu) [Member]    
Derivatives, Fair Value [Line Items]    
Derivative, nonmonetary notional amount | MMBTU 5,264 6,160
Electricity (in GWh) [Member]    
Derivatives, Fair Value [Line Items]    
Derivative, nonmonetary notional amount | GWh 438,863 428,367
Financial Transmission Rights [Member]    
Derivatives, Fair Value [Line Items]    
Derivative, nonmonetary notional amount | GWh 217,350 199,648
Coal (in tons) [Member]    
Derivatives, Fair Value [Line Items]    
Derivative, nonmonetary notional amount | T 20 22
Fuel oil (in gallons) [Member]    
Derivatives, Fair Value [Line Items]    
Derivative, nonmonetary notional amount | gal 176 33
Emissions (certificates) [Member]    
Derivatives, Fair Value [Line Items]    
Derivative, nonmonetary notional amount | T 8 20
Renewable energy certificate [Member]    
Derivatives, Fair Value [Line Items]    
Derivative, nonmonetary notional amount 18 11
Interest rate swaps, variable/fixed    
Derivatives, Fair Value [Line Items]    
Derivative, notional amount | $ $ 6,720 $ 6,720
Interest rate swaps, fixed/variable    
Derivatives, Fair Value [Line Items]    
Derivative, notional amount | $ $ 2,120 $ 2,120
v3.20.4
Commodity And Other Derivative Contractual Assets And Liabilities (Credit Risk-Related Contingent Features of Derivatives) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Credit Derivatives [Line Items]    
Derivative, net liability position, aggregate fair value $ (679) $ (692)
Credit risk derivative with contingent feature [Member]    
Credit Derivatives [Line Items]    
Derivative, net liability position, aggregate fair value 262 167
Collateral already posted, aggregate fair value 35 67
Cross-default credit derivative [Member]    
Credit Derivatives [Line Items]    
Assets needed for immediate settlement, aggregate fair value $ (382) $ (458)
v3.20.4
Commodity And Other Derivative Contractual Assets And Liabilities (Concentrations of Credit Risk Related to Derivatives) (Details) - Credit risk contract [Member]
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
Derivative [Line Items]  
Total credit risk exposure to all counterparties related to derivative contracts $ 1,085
Net exposure to those counterparties after taking into effect master netting arrangements, setoff provisions and collateral 293
Largest net exposure to single counterparty $ 85
Credit risk exposure to Banking and financial sector percentage 65.00%
Net exposure to banking and financial sector percentage 18.00%
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Narrative) (Details)
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
corporate_bond
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Apr. 09, 2018
USD ($)
Defined Benefit Plan Disclosure [Line Items]        
Market-related value of assets held in trust, realized and unrealized gains or losess, included in preceding period, related to vesting percentage 25.00%      
Assumed discount rate, number of corporate bonds used to derive yield curve | corporate_bond 305      
Pension And Other Postretirement Employee Benefit Plans Assumed in Merger [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Projected pension benefit obligation       $ 539
Assets       459
Assets for plan benefits, defined benefit plan       15
Liability, defined benefit plan, current       2
Liability, defined benefit plan, noncurrent       $ 93
Pension Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Projected pension benefit obligation $ 643 $ 674 $ 615  
Liability, defined benefit plan, noncurrent 158 146    
Employer contributions to retirement plan 16 0 12  
Expected future employer contributions to retirement plan 1      
Other Postretirement Benefits Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Projected pension benefit obligation 157 151 144  
Liability, defined benefit plan, current 9 9    
Liability, defined benefit plan, noncurrent 134 126    
Employer contributions to retirement plan 9 $ 9 $ 8  
Expected future employer contributions to retirement plan $ 9      
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Pension and OPEB Costs Recognized as Expense) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]      
Benefit costs $ 18 $ 20 $ 23
Pension Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Benefit costs 11 9 14
Other Postretirement Benefits Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Benefit costs $ 7 $ 11 $ 9
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Detailed Information Regarding Pension and Other Postretirement Benefits) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Components of Net Pension/OPEB Cost:            
Net periodic pension/OPEB cost $ 18 $ 20 $ 23      
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income:            
Net (gain) loss 23 11 9      
Change in Plan Assets:            
Fair value of assets at beginning of period 37          
Fair value of assets at end of year 41 37        
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]            
Fair value of assets 37 37   $ 41 $ 37  
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]            
Other noncurrent assets       332 352  
Pension Plan [Member]            
Components of Net Pension/OPEB Cost:            
Service cost 6 7 15      
Interest cost 20 25 21      
Expected return on assets (23) (26) (23)      
Amortization of unrecognized amounts 1 0 0      
Immediate pension cost 7 3 1      
Net periodic pension/OPEB cost 11 9 14      
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income:            
Net (gain) loss 17 11 14      
Total recognized in net periodic benefit cost and other comprehensive income 28 20 28      
Change in Pension/OPEB Obligation            
Projected benefit obligation at beginning of period 674 615        
Service cost 6 7 15      
Interest cost 20 25 21      
Lump-sum window (6) 0        
Annuity purchase (29) (18)        
Actuarial (gain) loss 46 93        
Benefits paid (68) (48)        
Projected benefit obligation at end of year 643 674 615      
Accumulated benefit obligation at end of year       639 669  
Change in Plan Assets:            
Fair value of assets at beginning of period 528 490        
Employer contributions 16 0 12      
Lump-sum window 6 0        
Annuity purchase (29) (18)        
Actual gain on assets 40 102        
Benefits paid (64) (46)        
Fair value of assets at end of year 485 528 490      
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]            
Projected pension benefit obligation (674) (674) (615) (643) (674) $ (615)
Fair value of assets 528 528 490 485 528 $ 490
Funded status at end of year       (158) (146)  
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]            
Other noncurrent liabilities       (158) (146)  
Net liability recognized       (158) (146)  
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]            
Net loss       $ (42) $ (24)  
Defined Benefit Plan, net actuarial gain (loss) $ 29 $ 16 $ 14      
Pension Plan [Member] | Vistra Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Discount rate 3.24% 4.37% 3.74%      
Expected return on plan assets 4.44% 4.80% 4.56%      
Expected rate of compensation increase 3.29% 3.35% 3.62%      
Interest crediting rate for cash balance plans 3.50% 3.50% 3.50%      
Pension Plan [Member] | Dynegy Plan and EEI Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Discount rate 3.24% 4.37% 4.05%      
Expected rate of compensation increase 3.29% 3.35% 3.50%      
Interest crediting rate for cash balance plans 3.50% 3.50% 4.25%      
Pension Plan [Member] | Dynegy Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Expected return on plan assets 5.28% 5.31% 5.94%      
Pension Plan [Member] | EEI Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Expected return on plan assets 5.45% 5.56% 4.74%      
Pension Plan [Member] | Vistra Plan, Dynegy Plan And EEI Plan            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost            
Discount rate       2.50% 3.24% 4.37%
Expected rate of compensation increase       3.41% 3.29% 3.35%
Interest crediting rate for cash balance plan 3.00% 3.50% 3.50%      
Other Postretirement Benefits Plan [Member]            
Components of Net Pension/OPEB Cost:            
Service cost $ 2 $ 2 $ 2      
Interest cost 4 6 5      
Expected return on assets (2) (1) (1)      
Amortization of unrecognized amounts 4 3 3      
Immediate pension cost (1) 1 0      
Net periodic pension/OPEB cost 7 11 9      
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income:            
Net (gain) loss and prior service (credit) cost 5 0 (6)      
Total recognized in net periodic benefit cost and other comprehensive income 12 11 3      
Change in Pension/OPEB Obligation            
Projected benefit obligation at beginning of period 151 144        
Service cost 2 2 2      
Interest cost 4 6 5      
Participant contributions 3 3        
Actuarial (gain) loss 12 10        
Benefits paid (15) (14)        
Projected benefit obligation at end of year 157 151 144      
Change in Plan Assets:            
Fair value of assets at beginning of period 34 29        
Employer contributions 9 9 8      
Participant contributions 3 3        
Actual gain on assets 4 6        
Benefits paid (13) (13)        
Fair value of assets at end of year 37 34 29      
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]            
Projected pension benefit obligation (151) (151) (144) $ (157) $ (151) $ (144)
Fair value of assets 34 34 29 37 34 $ 29
Funded status at end of year       (120) (117)  
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]            
Other noncurrent assets       23 18  
Other current liabilities       (9) (9)  
Other noncurrent liabilities       (134) (126)  
Net liability recognized       (120) (117)  
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]            
Net loss       $ 20 $ 15  
Defined Benefit Plan, net actuarial gain (loss) $ 10 $ 5 $ (7)      
Other Postretirement Benefits Plan [Member] | Vistra Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Discount rate 3.25% 4.35% 3.67%      
Other Postretirement Benefits Plan [Member] | Dynegy Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Discount rate 3.25% 4.35% 4.04%      
Other Postretirement Benefits Plan [Member] | Vistra Plan, Dynegy Plan And EEI Plan            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost            
Discount rate       2.51% 3.25% 4.35%
Other Postretirement Benefits Plan [Member] | Split-Participant Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Discount rate 3.25% 4.35% 3.67%      
Other Postretirement Benefits Plan [Member] | EEI Union Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Expected return on plan assets 7.07% 5.36% 5.10%      
Other Postretirement Benefits Plan [Member] | EEI Salaried Plan [Member]            
Assumptions Used to Determine Net Periodic Pension/OPEB Cost:            
Expected return on plan assets 3.43% 4.70% 4.47%      
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Projected Benefit Obligation (PBO) and Accumulated Benefit Obligation (ABO) in Excess of the Fair Value of Plan Assets) (Details) - Pension Plan [Member] - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]    
Projected benefit obligations $ 643 $ 674
Accumulated benefit obligation 639 669
Plan assets $ 485 $ 528
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Target Asset Allocation Ranges of Pension Plan Investments by Asset Category) (Details) - Pension Plan [Member]
12 Months Ended
Dec. 31, 2020
Vistra Plan [Member] | Fixed income securities [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 65
Vistra Plan [Member] | Fixed income securities [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 75
Vistra Plan [Member] | Global equity securities [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 16
Vistra Plan [Member] | Global equity securities [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 24
Vistra Plan [Member] | Real Estate [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 4
Vistra Plan [Member] | Real Estate [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 8
Vistra Plan [Member] | Credit strategies [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 3
Vistra Plan [Member] | Credit strategies [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 7
Dynegy Plan [Member] | Fixed income securities [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 45
Dynegy Plan [Member] | Fixed income securities [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 55
Dynegy Plan [Member] | Global equity securities [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 30
Dynegy Plan [Member] | Global equity securities [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 38
Dynegy Plan [Member] | Real Estate [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 8
Dynegy Plan [Member] | Real Estate [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 12
Dynegy Plan [Member] | Credit strategies [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 6
Dynegy Plan [Member] | Credit strategies [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 10
EEI Plan [Member] | Fixed income securities [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 40
EEI Plan [Member] | Fixed income securities [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 50
EEI Plan [Member] | Global equity securities [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 34
EEI Plan [Member] | Global equity securities [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 42
EEI Plan [Member] | Real Estate [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 10
EEI Plan [Member] | Real Estate [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 14
EEI Plan [Member] | Credit strategies [Member] | Minimum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 7
EEI Plan [Member] | Credit strategies [Member] | Maximum  
Defined Benefit Plan Disclosure [Line Items]  
Target Allocation Ranges 11
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Expected Long-Term Rate of Return on Assets Assumption) (Details) - Pension Plan [Member]
12 Months Ended
Dec. 31, 2020
Vistra Plan [Member] | Weighted Average [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 3.80%
Vistra Plan [Member] | Fixed income securities [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 2.40%
Vistra Plan [Member] | Global equity securities [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 7.30%
Vistra Plan [Member] | Real Estate [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 5.60%
Vistra Plan [Member] | Credit Strategies [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 4.80%
Dynegy Plan [Member] | Weighted Average [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 4.40%
Dynegy Plan [Member] | Fixed income securities [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 2.30%
Dynegy Plan [Member] | Global equity securities [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 7.30%
Dynegy Plan [Member] | Real Estate [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 5.60%
Dynegy Plan [Member] | Credit Strategies [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 4.80%
EEI Plan [Member] | Weighted Average [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 4.70%
EEI Plan [Member] | Fixed income securities [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 2.30%
EEI Plan [Member] | Global equity securities [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 7.30%
EEI Plan [Member] | Real Estate [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 5.60%
EEI Plan [Member] | Credit Strategies [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
Expected Long-term Rate of Return 4.80%
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Fair Value of Pension Plan Assets) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Fair value of assets $ 41 $ 37  
Pension Plan [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Fair value of assets 485 528 $ 490
Pension Plan [Member] | Fair Value, Recurring [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Assets measured at net asset value 485 528  
Pension Plan [Member] | Commingled Trusts [Member] | Fair Value, Recurring [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Assets measured at net asset value 11 10  
Pension Plan [Member] | Global equity securities [Member] | Fair Value, Recurring [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Assets measured at net asset value 153 169  
Pension Plan [Member] | Corporate Bond Securities [Member] | Fair Value, Recurring [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Assets measured at net asset value 207 211  
Pension Plan [Member] | Government Bond Securities [Member] | Fair Value, Recurring [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Assets measured at net asset value 37 50  
Pension Plan [Member] | Other Security Investments [Member] | Fair Value, Recurring [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Assets measured at net asset value 32 37  
Pension Plan [Member] | Real Estate Investment [Member] | Fair Value, Recurring [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Assets measured at net asset value 45 51  
Other Postretirement Benefits Plan [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Fair value of assets 37 34 $ 29
Other Postretirement Benefits Plan [Member] | Level 1 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Fair value of assets 29 26  
Other Postretirement Benefits Plan [Member] | Level 2 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Fair value of assets $ 8 $ 8  
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Assumed Health Care Cost Trend Rates) (Details) - Other Postretirement Benefits Plan [Member]
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Not Medicare Eligible [Member]    
Assumed Health Care Cost Trend Rates [Abstract]    
Health care cost trend rate assumed for next year 6.20% 6.40%
Rate to which the cost trend is expected to decline (the ultimate trend rate) 4.50% 4.50%
Year that the rate reaches the ultimate trend rate 2029 2029
Vistra Plan, EEI Union Plan And EEI Salaried Plan    
Assumed Health Care Cost Trend Rates [Abstract]    
Health care cost trend rate assumed for next year 9.10% 8.60%
Split-Participant Plan [Member]    
Assumed Health Care Cost Trend Rates [Abstract]    
Health care cost trend rate assumed for next year 8.80% 8.30%
Medicare Eligible [Member]    
Assumed Health Care Cost Trend Rates [Abstract]    
Rate to which the cost trend is expected to decline (the ultimate trend rate) 4.50% 4.50%
Year that the rate reaches the ultimate trend rate 2030 2029
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Future Benefit Payments) (Details)
$ in Millions
Dec. 31, 2020
USD ($)
Pension Plan [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
2021 $ 49
2022 43
2023 43
2024 40
2025 52
2026-30 188
Other Postretirement Benefits Plan [Member]  
Defined Benefit Plans and Other Postretirement Benefit Plans  
2021 10
2022 10
2023 10
2024 10
2025 9
2026-30 $ 41
v3.20.4
Pension and Other Postretirement Employee Benefits (OPEB) Plans (Qualified Savings Plan) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]      
Maximum amount employee may contribute if earnings are less that IRS threshold 75.00%    
Percent of employees pay eligible to be matched by employer 6.00%    
Employer contributions to the Thrift Plan $ 34 $ 27 $ 24
Qualified Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Percent of employees contribution matched by employer 100.00%    
Traditional Retirement Plan Formula Of Retirement Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Percent of employees contribution matched by employer 75.00%    
Minimum      
Defined Benefit Plan Disclosure [Line Items]      
Percent of employees pay eligible for contribution to plan, maximum 1.00%    
Maximum      
Defined Benefit Plan Disclosure [Line Items]      
Percent of employees pay eligible for contribution to plan, maximum 20.00%    
v3.20.4
Stock-Based Compensation (Vistra 2016 Omnibus Incentive Plan) (Details) - shares
Dec. 31, 2020
Oct. 03, 2016
Vistra Energy 2016 Omnibus Incentive Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of shares authorized for issuance as equity-based awards 37,500,000 22,500,000
v3.20.4
Stock-Based Compensation (Share-Based Compensation Arrangement Assumed in Merger) (Details)
$ in Millions
Apr. 09, 2018
USD ($)
shares
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award fair value of awards at Merger Date $ 89
Share-based compensation arrangement by share-based payment award fair value of award at Merger Date considered part of purchase price 26
Share-based compensation arrangement by share-based payment award fair value of award at Merger Date recognized as compensation expense 33
Share-based compensation arrangement by share-based payment award fair value of award at Merger Date to be amortized as compensation expense over the remaining service period 30
Share-based payment arrangement, option [Member]  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award fair value of awards at Merger Date $ 10
Share-based payment arrangement, option [Member] | Vistra Corp. [Member]  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award at Merger Date | shares 2,670,610
Share-based payment arrangement, option [Member] | Dynegy Inc.  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award prior to Merger Date | shares 4,096,027
Restricted Stock Units (RSUs) [Member]  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award fair value of awards at Merger Date $ 61
Restricted Stock Units (RSUs) [Member] | Vistra Corp. [Member]  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award at Merger Date | shares 3,056,689
Restricted Stock Units (RSUs) [Member] | Dynegy Inc.  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award prior to Merger Date | shares 5,718,148
Performance Shares [Member]  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award fair value of awards at Merger Date $ 18
Performance Shares [Member] | Vistra Corp. [Member]  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award at Merger Date | shares 938,721
Performance Shares [Member] | Dynegy Inc.  
Stock-Based Compensation Awards Assumed in Merger [Line Items]  
Share-based compensation arrangement by share-based payment award prior to Merger Date | shares 1,538,133
v3.20.4
Stock-Based Compensation (Stock-Based Compensation Expense) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Payment Arrangement [Abstract]      
Total stock-based compensation expense $ 63 $ 47 $ 73
Income tax benefit (15) (9) (15)
Stock based-compensation expense, net of tax $ 48 $ 38 $ 58
v3.20.4
Stock-Based Compensation (Summary of Stock Options Activity) (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
12 Months Ended
Apr. 09, 2018
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Assumed dividend yield   2.30% 1.90%
Share-based payment arrangement, option [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation arrangement by share-based payment award, options, grants in period, gross 5,200 3,014  
Unrecognized compensation cost related to unvested stock options granted   $ 27.0  
Unrecognized compensation cost related to unvested stock options granted, weighted average recognition period   2 years  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Total outstanding at beginning of period (number)   13,535  
Granted (number) 5,200 3,014  
Exercised (number)   (251)  
Forfeited or expired (number)   (268)  
Total outstanding at end of period (number)   16,030 13,535
Exercisable (number)   6,871  
Total outstanding at beginning of period (weighted average exercise price)   $ 18.73  
Granted (weighted average exercise price)   22.98  
Exercised (weighted average exercise price)   13.62  
Forfeited or expired (weighted average exercise price)   20.74  
Total outstanding at end of the period (weighted average exercise price)   19.58 $ 18.73
Exercisable (weighted average exercise price)   $ 16.83  
Total outstanding (weighted average remaining contractual term)   6 years 8 months 12 days 7 years 3 months 18 days
Exercisable (weighted average remaining contractual term)   5 years 10 months 24 days  
Total outstanding at beginning of period (aggregate intrinsic value)   $ 69.3  
Total outstanding at end of period (aggregate intrinsic value)   30.8 $ 69.3
Exercisable (aggregate intrinsic value)   $ 30.5  
Share-based payment arrangement, option [Member] | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Graded vesting period for recognizing stock-based compensation cost   4  
Share-based payment arrangement, option [Member] | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Graded vesting period for recognizing stock-based compensation cost   5 years  
v3.20.4
Stock-Based Compensation (Summary of Restrict Stock Unit Activity) (Details) - Restricted Stock Units (RSUs) [Member]
$ / shares in Units, shares in Thousands, $ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Total outstanding at beginning of period (number) | shares 2,538
Granted (number) | shares 1,209
Vested (number) | shares (1,456)
Forfeited (number) | shares (39)
Total outstanding at end of period (number) | shares 2,252
Total outstanding at beginning of period (weighted average grant date fair value) | $ / shares $ 20.99
Granted (weighted average grant date fair value) | $ / shares 22.50
Vested (weighted average grant date fair value) | $ / shares 19.48
Forfeited or expired (weighted average grant date fair value) | $ / shares 21.89
Total outstanding at end of period (weighted average grant date fair value) | $ / shares $ 22.35
Unrecognized compensation cost related to unvested restricted stock units granted | $ $ 27
Unrecognized compensation cost related to unvested restricted stock units granted, weighted average recognition period 2 years
v3.20.4
Stock-Based Compensation (Summary of Performance Stock Units Activity (Details) - Performance Shares [Member]
$ / shares in Units, shares in Thousands, $ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Total outstanding at beginning of period (number) | shares 0
Granted (number) | shares 473
Vested (number) | shares (21)
Forfeited (number) | shares (1)
Total outstanding at end of period (number) | shares 451
Total outstanding at beginning of period (weighted average grant date fair value) | $ / shares $ 0
Granted (weighted average grant date fair value) | $ / shares 23.43
Vested (weighted average grant date fair value) | $ / shares 23.43
Forfeited or expired (weighted average grant date fair value) | $ / shares 23.43
Total outstanding at end of period (weighted average grant date fair value) | $ / shares $ 23.43
Performance period 3 years
Unrecognized compensation cost related to unvested restricted stock units granted | $ $ 4
Unrecognized compensation cost related to unvested stock options granted, weighted average recognition period 3 months
Minimum  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Award vesting rights, percentage 0.00%
Maximum  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Award vesting rights, percentage (200.00%)
Median  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Award vesting rights, percentage (100.00%)
October 2017 Issuance  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Award vesting period 13 months
February 2019 Issuance  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Award vesting period 12 months
v3.20.4
Related Party Transactions (Narrrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Related Party Transaction [Line Items]      
Stock repurchased during period, shares   0 0
Maximum      
Related Party Transaction [Line Items]      
Registration Rights Agreement, Demand Registration, number of days to File S-1 Registration Statement 45 days    
Registration Rights Agreement, Demand Registration, number of days to file S-3 Registration Statement 30 days    
Registration Rights Agreement, Demand Registration, number of days between initial registration and effective date 120 days    
Legal Expenses Paid On Behalf of Selling Stockholders [Member]      
Related Party Transaction [Line Items]      
Legal fees $ 1 $ 1 $ 1
Apollo Management Holdings L.P. [Member]      
Related Party Transaction [Line Items]      
Stock repurchased during period, shares     5,000,000
Shareholder's trading shares     17,000,000
Stockholders' equity, other shares     12,000,000
v3.20.4
Segment Information (Details)
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
Reportable_segment
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Segment Reporting Information [Line Items]      
Number of reportable segments (in reportable segments) | Reportable_segment 6    
Operating revenues $ 11,443 $ 11,809 $ 9,144
Depreciation and amortization (1,737) (1,640) (1,394)
Operating income (loss) 1,519 1,993 491
Interest expense and related charges (630) (797) (572)
Income tax expense (benefit) (266) (290) 45
Net income (loss) 624 926 (56)
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 600 487 396
Unrealized gain loss on commodity related derivatives 231 696 (380)
Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives 164 682 (380)
Corporate, Non-Segment [Member]      
Segment Reporting Information [Line Items]      
Operating revenues 0 0 0
Depreciation and amortization (64) (57) (72)
Operating income (loss) (137) (127) (320)
Interest expense and related charges (632) (770) (612)
Income tax expense (benefit) (266) (290) 45
Net income (loss) (1,021) (1,204) (912)
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 91 69 50
Corporate, Non-Segment [Member] | Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives 0 0 0
Intersegment Eliminations [Member]      
Segment Reporting Information [Line Items]      
Operating revenues (4,895) (3,970) (2,607)
Depreciation and amortization 0 0 0
Operating income (loss) 0 1 0
Interest expense and related charges 3 3 71
Income tax expense (benefit) 0 0 0
Net income (loss) 0 1 0
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 0 0 0
Intersegment Eliminations [Member] | Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives (329) (305) 217
Retail Segment [Member]      
Segment Reporting Information [Line Items]      
Operating revenues 8,270 6,872 5,597
Depreciation and amortization (303) (292) (318)
Operating income (loss) 312 155 690
Interest expense and related charges (10) (21) (7)
Income tax expense (benefit) 0 0 0
Net income (loss) 309 134 712
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 2 1 1
Retail Segment [Member] | Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives (11) 8 (12)
Texas Segment [Member]      
Segment Reporting Information [Line Items]      
Operating revenues 4,116 3,836 2,497
Depreciation and amortization (475) (472) (390)
Operating income (loss) 1,761 1,314 (103)
Interest expense and related charges 8 8 (12)
Income tax expense (benefit) 0 0 0
Net income (loss) 1,760 1,342 (88)
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 388 296 280
Texas Segment [Member] | Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives 677 575 (483)
East Segment [Member]      
Segment Reporting Information [Line Items]      
Operating revenues 2,415 2,790 1,895
Depreciation and amortization (721) (680) (519)
Operating income (loss) 73 398 10
Interest expense and related charges (7) (13) (10)
Income tax expense (benefit) 0 0 0
Net income (loss) 41 400 18
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 71 61 21
East Segment [Member] | Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives (23) 195 (76)
West Segment [Member]      
Segment Reporting Information [Line Items]      
Operating revenues 282 338 208
Depreciation and amortization (19) (19) (14)
Operating income (loss) 39 88 35
Interest expense and related charges 10 0 (1)
Income tax expense (benefit) 0 0 0
Net income (loss) 50 88 34
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 2 2 8
West Segment [Member] | Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives (10) 41 (15)
Sunset Segment [Member]      
Segment Reporting Information [Line Items]      
Operating revenues 1,252 1,602 1,183
Depreciation and amortization (133) (120) (81)
Operating income (loss) (420) 271 242
Interest expense and related charges (2) (4) (1)
Income tax expense (benefit) 0 0 0
Net income (loss) (414) 274 242
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 46 58 36
Sunset Segment [Member] | Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives (140) 168 (11)
Asset Closure Segment [Member]      
Segment Reporting Information [Line Items]      
Operating revenues 3 341 371
Depreciation and amortization (22) 0 0
Operating income (loss) (109) (107) (63)
Interest expense and related charges 0 0 0
Income tax expense (benefit) 0 0 0
Net income (loss) (101) (109) (62)
Capital expenditures, including nuclear fuel and excluding LTSA prepayments and development and growth expenditures 0 0 0
Asset Closure Segment [Member] | Operating revenues [Member]      
Segment Reporting Information [Line Items]      
Unrealized gain loss on commodity related derivatives $ 0 $ 0 $ 0
v3.20.4
Supplementary Financial Information (Impairment of Long-Lived Assets) (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Sep. 30, 2020
Mar. 31, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets     $ 356 $ 0 $ 0
Sunset Segment [Member] | Kincaid Generation, property, plant and equipment and inventory [Member]          
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets $ 173        
Sunset Segment [Member] | William H. Zimmer Power Station, property, plant and equipment and inventory [Member]          
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets 99        
Sunset Segment [Member] | Newton Generation And William H. Zimmer Power Station, property, plant and equipment [Member]          
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets 260        
Sunset Segment [Member] | Newton Generation And William H. Zimmer Power Station, inventory [Member]          
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets $ 12        
Sunset Segment [Member] | Joppa/EEI Power Plant, property, plant and equipment and inventory [Member]          
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets   $ 52      
Sunset Segment [Member] | Joppa/EEI Power Plant, property, plant and equipment [Member]          
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets   45      
Sunset Segment [Member] | Joppa/EEI Power Plant, intangible asset [Member]          
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets   32      
Sunset Segment [Member] | Joppa/EEI Power Plant, inventory [Member]          
Impaired Long-Lived Assets Held and Used [Line Items]          
Impairment of long-lived assets   $ 7      
v3.20.4
Supplementary Financial Information (Interest Expense and Related Charges) (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Jun. 30, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Interest Expense and Related Charges [Line Items]        
Interest paid/accrued   $ 467 $ 576 $ 537
Unrealized mark-to-market net losses on interest rate swaps   155 220 5
Amortization of debt issuance costs, discounts and premiums   18 9 0
Debt extinguishment (gain) loss   (17) (21) 27
Capitalized interest   (21) (12) (12)
Other   28 25 15
Total interest expense and related charges   $ 630 $ 797 $ 572
Vistra Operations Company LLC [Member] | Line of Credit [Member]        
Interest Expense and Related Charges [Line Items]        
Debt extinguishment (gain) loss $ (4)      
Debt instrument, interest rate curing period   3.88% 4.03% 4.24%
v3.20.4
Supplementary Financial Information (Other Income and Deductions) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Insurance settlement $ 6    
Interest income 2 $ 10 $ 18
All other 18 15 2
Total other income 34 56 47
Loss on disposal of investment in NELP 29 0 0
All other 13 15 5
Total other deductions 42 15 5
Corporate, Non-Segment [Member]      
Insurance settlement 3    
Funds released from escrow to settle pre-petition claims of our predecessor 0 9 0
Office space sublease rental income 0 0 8
Texas Segment [Member]      
Insurance settlement 1 22 16
Sale of land   0 3
East Segment [Member]      
Loss on disposal of investment in NELP 29 $ 0 $ 0
Asset Closure Segment [Member]      
Insurance settlement 2    
Sale of land $ 8    
v3.20.4
Supplementary Financial Information (Restricted Cash) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Restricted cash $ 19 $ 147
Restricted cash 19 28
Amounts Related To Remediation Escrow Accounts    
Restricted cash 19 15
Restricted cash 19 28
Amounts related to restructuring escrow accounts [Member]    
Restricted cash 0 43
Restricted cash 0 0
Amounts Related To Ambit Customer Deposits    
Restricted cash 0 19
Restricted cash 0 0
Amounts Related To Ambit Commodity Trading Agreement    
Restricted cash 0 62
Restricted cash 0 0
Amounts Related To Ambit Letters Of Credit    
Restricted cash 0 8
Restricted cash $ 0 $ 0
v3.20.4
Supplementary Financial Information (Pre-Petition Claims) (Details)
$ in Billions
Oct. 03, 2016
USD ($)
Supplementary Financial Information [Abstract]  
Fresh-start adjustment, increase (decrease), liabilities subject to compromise $ 33.8
v3.20.4
Supplementary Financial Information (Trade Accounts Receivable and Allowance for Doubtful Accounts) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2020
Jan. 01, 2020
Dec. 31, 2019
Jan. 01, 2019
Jan. 01, 2018
Wholesale and retail trade accounts receivable       $ 1,324   $ 1,401    
Allowance for uncollectible accounts $ (45) $ (19) $ (19) (45)   (36) $ (19) $ (14)
Trade accounts receivable - net       1,279   1,365    
Unbilled receivables, current       $ 468   494    
Accounts Receivable, Allowance for Credit Loss [Roll Forward]                
Allowance for uncollectible accounts receivable at beginning of period (a) 36 19            
Increase for bad debt expense 110 82 56          
Decrease for account write-offs (107) (65) (51)          
Allowance for uncollectible accounts receivable at end of period 45 36 $ 19          
Cumulative Effect, Period of Adoption, Adjusted Balance                
Allowance for uncollectible accounts (42) (42)       $ (42)    
Accounts Receivable, Allowance for Credit Loss [Roll Forward]                
Allowance for uncollectible accounts receivable at beginning of period (a) $ 42              
Allowance for uncollectible accounts receivable at end of period   $ 42            
Accounting Standards Update 2016-13 [Member]                
Allowance for uncollectible accounts         $ (6)      
v3.20.4
Supplementary Financial Information (Inventories by Major Category and Other Investments) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Inventories by Major Category    
Materials and supplies $ 260 $ 278
Fuel stock 236 172
Natural gas in storage 19 19
Total inventories 515 469
Other Investments    
Nuclear plant decommissioning trust 1,674 1,451
Assets related to employee benefit plans 41 37
Land 44 49
Total investments $ 1,759 $ 1,537
v3.20.4
Supplementary Financial Information (Investment in Unconsolidated Subsidiaries) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Apr. 09, 2018
Schedule of Equity Method Investments [Line Items]        
Investment in unconsolidated subsidiary $ 0 $ 124    
Income (loss) from equity method investments, net of dividends or distributions 3 14 $ 17  
Proceeds from equity method investment, distribution $ 3 22 $ 17  
Sayreville Plant [Member]        
Schedule of Equity Method Investments [Line Items]        
Jointly owned utility plant, proportionate ownership share 100.00%      
Northeast Energy, LP [Member] | Northeast Energy, LP [Member]        
Schedule of Equity Method Investments [Line Items]        
Noncontrolling interest in joint ventures       50.00%
North Jersey Energy Associates [Member] | Sayreville Plant [Member]        
Schedule of Equity Method Investments [Line Items]        
Jointly owned utility plant, proportionate ownership share 100.00%      
Northeast Energy, LP [Member]        
Schedule of Equity Method Investments [Line Items]        
Investment in unconsolidated subsidiary   $ 123    
v3.20.4
Supplementary Financial Information (Nuclear Decommissioning Trust) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Schedule of Schedule of Decommissioning Fund Investments [Line Items]      
Nuclear decommissioning trust $ 1,674 $ 1,451  
Proceeds from sales of securities 433 431 $ 252
Investments in securities (455) (453) $ (274)
Debt securities [Member]      
Schedule of Schedule of Decommissioning Fund Investments [Line Items]      
Nuclear decommissioning trust $ 618 $ 521  
Debt, weighted average interest rate 2.91% 3.42%  
Decommissioning Fund Investments, debt securities, average maturity 10 years 9 years  
Decommissioning Fund Investments, debt maturities, one through five years, fair value $ 193    
Decommissioning Fund Investments, debt maturities, five through ten years, fair value 185    
Decommissioning Fund Investments, debt maturities, after ten years, fair value 240    
Equity securities [Member]      
Schedule of Schedule of Decommissioning Fund Investments [Line Items]      
Nuclear decommissioning trust $ 1,056 $ 930  
v3.20.4
Supplementary Financial Information (Property, Plant and Equipment) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, gross $ 16,012 $ 15,991  
Less accumulated depreciation (3,614) (2,553)  
Net of accumulated depreciation 12,398 13,438  
Finance lease, right-of-use asset 182 59  
Nuclear fuel, net of amortization 207 197  
Construction work in progress, gross 712 220  
Property, plant and equipment — net 13,499 13,914  
Depreciation 1,377 1,300 $ 1,024
Power generation and structures [Member]      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, gross 15,222 15,205  
Land [Member]      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, gross 617 622  
Office and other equipment [Member]      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, gross 173 164  
Nuclear fuel [Member]      
Property, Plant and Equipment [Line Items]      
Less accumulated depreciation $ (91) $ (216)  
Minimum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 1 year    
Maximum      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, useful life 33 years    
v3.20.4
Supplementary Financial Information (Asset Retirement and Mining Reclamation Obligations) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Asset Retirement Obligations [Line Items]          
Regulatory liabilities       $ 89 $ 131
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]          
Beginning balance, liability $ 2,238 $ 2,373 $ 1,936    
Additions:          
Accretion 89 97 93    
Adjustment for change in estimates 238 15 (33)    
Adjustment for obligations assumed through the Merger or acquisitions   (3) 477    
Reductions:          
Payments (114) (109) (100)    
Liability transfers 15 135      
Ending balance, liability 2,238 2,373 1,936 2,436 2,238
Less amounts due currently       (103) (141)
Noncurrent liability at end of period 2,333 2,097      
Nuclear Plant Decommissioning [Member]          
Asset Retirement Obligations [Line Items]          
Regulatory liabilities       89  
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]          
Beginning balance, liability 1,320 1,276 1,233    
Additions:          
Accretion 46 44 43    
Adjustment for change in estimates 219 0 0    
Adjustment for obligations assumed through the Merger or acquisitions   0 0    
Reductions:          
Payments 0 0 0    
Liability transfers 0        
Ending balance, liability 1,320 1,276 1,233 1,585 1,320
Less amounts due currently       0  
Noncurrent liability at end of period 1,585        
Mining Land Reclamation [Member]          
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]          
Beginning balance, liability 410 442 438    
Additions:          
Accretion 20 22 22    
Adjustment for change in estimates (6) 16 56    
Adjustment for obligations assumed through the Merger or acquisitions   0 2    
Reductions:          
Payments (65) (70) (76)    
Liability transfers 0 0      
Ending balance, liability 410 442 438 359 410
Less amounts due currently       (92)  
Noncurrent liability at end of period 267        
Coal Ash and Other [Member]          
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]          
Beginning balance, liability 508 655 265    
Additions:          
Accretion 23 31 28    
Adjustment for change in estimates 25 (1) (89)    
Adjustment for obligations assumed through the Merger or acquisitions   (3) 475    
Reductions:          
Payments (49) (39) (24)    
Liability transfers 15 135      
Ending balance, liability 508 $ 655 $ 265 492 $ 508
Less amounts due currently       $ (11)  
Noncurrent liability at end of period $ 481        
v3.20.4
Supplementary Financial Information (Other Noncurrent Liabilities and Deferred Credits) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Supplementary Financial Information [Abstract]    
Retirement and other employee benefits $ 312 $ 295
Identifiable intangible liabilities 289 286
Regulatory liabilities 89 131
Finance lease liabilities 206 78
Uncertain tax positions, including accrued interest 12 10
Liability for third-party remediation 31 41
Environmental allowances 0 52
Accrued severance costs 54 12
Other accrued expenses 138 84
Other noncurrent liabilities and deferred credits $ 1,131 $ 989
v3.20.4
Supplementary Financial Information (Fair Value of Debt) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Reported Value Measurement [Member] | Long-term debt under the Vistra Operations Credit Facility [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure $ 2,579 $ 2,715
Reported Value Measurement [Member] | Vistra Operations Senior Unsecured Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 6,634 6,620
Reported Value Measurement [Member] | Vistra Senior Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 0 774
Reported Value Measurement [Member] | Forward Capacity Agreements [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 45 155
Reported Value Measurement [Member] | Equipment Financing Agreements [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 59 87
Reported Value Measurement [Member] | Building financing [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 10 16
Reported Value Measurement [Member] | Other debt [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 3 12
Estimate of Fair Value Measurement [Member] | Level 2 [Member] | Long-term debt under the Vistra Operations Credit Facility [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 2,565 2,717
Estimate of Fair Value Measurement [Member] | Level 2 [Member] | Vistra Operations Senior Unsecured Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 7,204 6,926
Estimate of Fair Value Measurement [Member] | Level 2 [Member] | Vistra Senior Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 0 772
Estimate of Fair Value Measurement [Member] | Level 2 [Member] | Building financing [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 10 16
Estimate of Fair Value Measurement [Member] | Level 3 [Member] | Forward Capacity Agreements [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 45 155
Estimate of Fair Value Measurement [Member] | Level 3 [Member] | Equipment Financing Agreements [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure 59 87
Estimate of Fair Value Measurement [Member] | Level 3 [Member] | Other debt [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Instrument, fair value disclosure $ 3 $ 12
v3.20.4
Supplementary Financial Information (Supplemental Cash Flow Information) (Details) - USD ($)
shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Supplementary Financial Information [Abstract]        
Cash and cash equivalents $ 406 $ 300    
Restricted cash included in current assets 19 147    
Restricted cash included in noncurrent assets 19 28    
Total cash, cash equivalents and restricted cash 444 475 $ 693 $ 2,046
Cash payments related to:        
Interest paid 503 525 651  
Capitalized interest (21) (12) (12)  
Interest paid (net of capitalized interest) 482 513 639  
Income taxes paid / (refunds received) (140) (76) 67  
Noncash investing and financing activities:        
Construction expenditures 19 67 84  
Disposition of investment in NELP 123 0 0  
Acquisition of investment in NJEA 90 0 0  
Shares issued for tangible equity unit contracts 0 446 0  
Land transferred with liability transfers $ 0 $ 16 $ 0  
Vistra common stock issued in the Merger 0 0 2,245  
Domestic Tax Authority [Member]        
Income Tax Contingency [Line Items]        
Taxes paid $ 0 $ 0 $ 45  
Proceeds from income tax refunds (170) (115) 0  
State and Local Jurisdiction [Member]        
Income Tax Contingency [Line Items]        
Taxes paid 40 42 27  
Proceeds from income tax refunds $ (10) $ (3) $ (5)  
v3.20.4
Schedule I - Condensed Financial Information (Parent Company) (Condensed Statements of Operations) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]      
Depreciation and amortization $ (1,737) $ (1,640) $ (1,394)
Selling, general and administrative expenses (1,035) (904) (926)
Operating income 1,519 1,993 491
Other income 34 56 47
Interest expense and related charges (630) (797) (572)
Impacts of Tax Receivable Agreement 5 (37) (79)
Income (loss) before income taxes 890 1,216 (101)
Income tax (expense) benefit (266) (290) 45
Net income (loss) 624 926 (56)
Parent [Member]      
Condensed Financial Statements, Captions [Line Items]      
Depreciation and amortization (15) (7) 0
Selling, general and administrative expenses (72) (62) (266)
Operating income (87) (69) (266)
Other income 5 12 9
Interest expense and related charges (7) (88) (257)
Impacts of Tax Receivable Agreement 5 (37) (79)
Income (loss) before income taxes (84) (182) (593)
Income tax (expense) benefit 25 42 282
Equity in earnings of subsidiaries, net of tax 695 1,068 257
Net income (loss) $ 636 $ 928 $ (54)
v3.20.4
Schedule I - Condensed Financial Information (Parent Company) (Condensed Statements of Cash Flows) (Details) - USD ($)
$ in Millions
12 Months Ended 24 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2019
Cash flows — operating activities:        
Cash provided by operating activities $ 3,337 $ 2,736 $ 1,471  
Cash flows — investing activities:        
Capital expenditures (1,259) (713) (530)  
Other, net 24 17 3  
Cash used in investing activities (1,572) (1,717) (101)  
Cash flows - financing activities:        
Repayments/repurchases of debt (1,008) (7,109) (3,075)  
Debt tender offer and other debt financing fees (17) (203) (236)  
Stock repurchase 0 (656) (763)  
Dividends paid to stockholders (266) (243) 0  
Other, net (5) 6 12  
Cash used in financing activities (1,796) (1,237) (2,723)  
Net change in cash, cash equivalents and restricted cash (31) (218) (1,353)  
Cash, cash equivalents and restricted cash — beginning balance 475 693 2,046 $ 2,046
Cash, cash equivalents and restricted cash — ending balance 444 475 693 475
Parent [Member]        
Cash flows — operating activities:        
Cash provided by operating activities (86) (58) (125)  
Cash flows — investing activities:        
Capital expenditures (15) (36) (24)  
Dividends received from subsidiaries 1,105 3,890 4,668  
Other, net 0 0 (1)  
Cash used in investing activities 1,090 3,854 4,643  
Cash flows - financing activities:        
Repayments/repurchases of debt (747) (2,903) (4,543)  
Debt tender offer and other debt financing fees (17) (123) (179)  
Stock repurchase 0 (656) (763)  
Dividends paid to stockholders (266) (243) 0  
Other, net 0 0 12  
Cash used in financing activities (1,030) (3,925) (5,473)  
Net change in cash, cash equivalents and restricted cash (26) (129) (955)  
Cash, cash equivalents and restricted cash — beginning balance 99 228 1,183 1,183
Cash, cash equivalents and restricted cash — ending balance $ 73 $ 99 $ 228 $ 99
v3.20.4
Schedule I - Condensed Financial Information (Parent Company) (Condensed Balance Sheets) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Current assets:        
Cash and cash equivalents $ 406 $ 300    
Restricted cash 19 147    
Trade accounts receivable — net 1,279 1,365    
Prepaid expense and other current assets 205 298    
Total current assets 3,429 4,114    
Property, plant and equipment — net 13,499 13,914    
Identifiable intangible assets — net 2,446 2,748    
Accumulated deferred income taxes 838 1,066    
Other noncurrent assets 332 352    
Total assets 25,208 26,616    
Current liabilities:        
Long-term debt due currently 95 277    
Trade accounts payable 880 947    
Accrued income taxes 16 1    
Accrued interest 131 151    
Other current liabilities 471 506    
Total current liabilities 3,036 4,574    
Long-term debt, less amounts due currently 9,235 10,102    
Tax Receivable Agreement obligation 447 455 $ 420  
Other noncurrent liabilities and deferred credits 1,131 989    
Total liabilities 16,847 18,656    
Equity [Abstract]        
Total equity 8,361 7,960 $ 7,867 $ 6,342
Total liabilities and equity 25,208 26,616    
Parent [Member]        
Current assets:        
Cash and cash equivalents 73 56    
Restricted cash 0 43    
Trade accounts receivable — net 7 5    
Prepaid expense and other current assets 5 100    
Total current assets 85 204    
Investment in affiliated companies 8,005 8,364    
Property, plant and equipment — net 3 4    
Identifiable intangible assets — net 47 49    
Accumulated deferred income taxes 783 729    
Other noncurrent assets 2 67    
Total assets 8,925 9,417    
Current liabilities:        
Long-term debt due currently 0 87    
Trade accounts payable 2 1    
Accounts payable - affiliates 74 145    
Accrued income taxes 14 1    
Accrued interest 0 11    
Other current liabilities 4 46    
Total current liabilities 94 291    
Long-term debt, less amounts due currently 0 689    
Tax Receivable Agreement obligation 447 455    
Other noncurrent liabilities and deferred credits 23 22    
Total liabilities 564 1,457    
Equity [Abstract]        
Total equity 8,361 7,960    
Total liabilities and equity $ 8,925 $ 9,417    
v3.20.4
Schedule I - Condensed Financial Information (Parent Company) (Notes to Condensed Financial Statements) (Details) - USD ($)
$ in Billions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]      
Maximum allowable distribution to parent company by consolidated subsidiary without consent $ 6.7    
Parent Company [Member]      
Condensed Financial Statements, Captions [Line Items]      
Cash dividends paid 1.1 $ 3.9 $ 4.7
Amount of restricted net assets $ 1.2