Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2015	Mar. 01, 2016	Jun. 30, 2015
Document and Entity Information
Entity Registrant Name	QWEST CORP
Entity Central Index Key	0000068622
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding (shares)		1
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
OPERATING REVENUES
Operating revenues	$ 6,557	$ 6,676	$ 6,818
Operating revenues - affiliates	2,407	2,162	1,935
Total operating revenues	8,964	8,838	8,753
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	2,872	2,879	2,790
Selling, general and administrative	1,015	1,086	1,062
Operating expenses - affiliates	960	756	695
Depreciation and amortization	1,857	2,005	2,128
Total operating expenses	6,704	6,726	6,675
OPERATING INCOME	2,260	2,112	2,078
OTHER (EXPENSE) INCOME
Interest expense	(473)	(464)	(450)
Interest expense - affiliates, net	(53)	(40)	(64)
Other (expense) income, net	(1)	1	2
Total other expense, net	(527)	(503)	(512)
INCOME BEFORE INCOME TAX EXPENSE	1,733	1,609	1,566
Income tax expense	659	639	602
NET INCOME	$ 1,074	$ 970	$ 964

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
CURRENT ASSETS
Cash and cash equivalents	$ 3	$ 6
Accounts receivable, less allowance of $47 and $38	688	740
Advances to affiliates	788	812
Other	123	125
Total current assets	1,602	1,683
NET PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	12,182	11,157
Accumulated depreciation	(4,808)	(3,956)
Net property, plant and equipment	7,374	7,201
GOODWILL AND OTHER ASSETS
Goodwill	9,354	9,354
Other intangible assets, net	613	808
Other, net	92	100
Total goodwill and other assets	12,494	13,301
TOTAL ASSETS	21,470	22,185
CURRENT LIABILITIES
Current maturities of long-term debt	242	117
Accounts payable	369	464
Note payable - affiliate	855	796
Accrued expenses and other liabilities
Salaries and benefits	211	220
Income and other taxes	189	197
Other	135	140
Current affiliate obligations, net	97	0
Advance billings and customer deposits	324	327
Total current liabilities	2,422	2,261
LONG-TERM DEBT	6,997	7,152
DEFERRED CREDITS AND OTHER LIABILITIES
Deferred revenues	137	153
Deferred income taxes, net	1,896	2,085
Affiliates obligations, net	1,051	1,271
Other	60	80
Total deferred credits and other liabilities	$ 3,144	$ 3,589
COMMITMENTS AND CONTINGENCIES (Note 15)
STOCKHOLDER'S EQUITY
Common stock - one share without par value, owned by Qwest Services Corporation	$ 10,050	$ 10,050
Accumulated deficit	(1,143)	(867)
Total stockholder's equity	8,907	9,183
TOTAL LIABILITIES AND STOCKHOLDER'S EQUITY	21,470	22,185
Customer Relationships
Customer relationships, net	$ 2,435	$ 3,039

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ / shares in Millions, $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts receivable, allowance (in dollars)	$ 47	$ 38
Common stock, share outstanding (shares)	1	1
Common stock, shares issued (shares)	1	1
Common stock outstanding, value	$ 10,050	$ 10,050
Common stock issued, value	$ 10,050	$ 10,050
Common stock, no par value	$ 10,050	$ 10,050

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
OPERATING ACTIVITIES
Net income	$ 1,074	$ 970	$ 964
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,857	2,005	2,128
Deferred income taxes	(189)	(228)	(152)
Provision for uncollectible accounts	78	64	65
Net long-term debt issuance costs and premium amortization	(18)	(38)	(51)
Accrued interest on affiliate note	59	42	0
Impairment of asset	0	17	0
Changes in current assets and liabilities:
Accounts receivable	(26)	(66)	(94)
Accounts payable	(79)	(9)	(1)
Accrued income and other taxes	(8)	(9)	(9)
Other current assets and liabilities, net	1	34	34
Other current assets and liabilities - affiliates	(4)	9	0
Changes in other noncurrent assets and liabilities, net	(30)	1	0
Changes in affiliate obligations, net	(123)	8	(179)
Other, net	(1)	1	8
Net cash provided by operating activities	2,591	2,801	2,713
INVESTING ACTIVITIES
Payments for property, plant and equipment and capitalized software	(1,247)	(1,165)	(1,264)
Changes in advances to affiliates	24	(100)	(119)
Proceeds from sale of property	3	14	2
Net cash used in investing activities	(1,220)	(1,251)	(1,381)
FINANCING ACTIVITIES
Net proceeds from issuance of long-term debt	495	483	752
Payments of long-term debt	(517)	(641)	(806)
Early retirement of debt costs	(2)	0	0
Dividends paid to Qwest Services Corporation	(1,350)	(1,400)	(1,325)
Changes in note payable - affiliate	0	0	53
Net cash used in financing activities	(1,374)	(1,558)	(1,326)
Net (decrease) increase in cash and cash equivalents,	(3)	(8)	6
Cash and cash equivalents at beginning of period	6	14	8
Cash and cash equivalents at end of period	3	6	14
Supplemental cash flow information:
Income taxes paid, net	(848)	(861)	(750)
Interest paid (net of capitalized interest of $18, $17 and $17)	$ (497)	$ (505)	$ (513)

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Cash Flows [Abstract]
Interest paid, capitalized interest	$ 18	$ 17	$ 17

CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY (DEFICIT) - USD ($) $ in Millions	Total	COMMON STOCK	ACCUMULATED DEFICIT
Balance at beginning of period at Dec. 31, 2012		$ 10,050	$ (76)
Increase (Decrease) in Stockholder's Equity
Net income	$ 964		964
Dividends declared to Qwest Services Corporation	(1,325)		(1,325)
Balance at end of period at Dec. 31, 2013	9,613	10,050	(437)
Increase (Decrease) in Stockholder's Equity
Net income	970		970
Dividends declared to Qwest Services Corporation	(1,400)		(1,400)
Balance at end of period at Dec. 31, 2014	9,183	10,050	(867)
Increase (Decrease) in Stockholder's Equity
Net income	1,074		1,074
Dividends declared to Qwest Services Corporation	(1,350)		(1,350)
Balance at end of period at Dec. 31, 2015	$ 8,907	$ 10,050	$ (1,143)

Basis of Presentation and Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Basis of Presentation and Summary of SIgnificant Accounting Policies

Basis of Presentation and Summary of Significant Accounting Policies

Basis of Presentation

We are an integrated communications company engaged primarily in providing an array of communications services to our residential and business customers. Our communications services include local voice, high-speed Internet, private line (including special access), network access, Ethernet, information technology, wireless, video and other ancillary services. In certain local and regional markets, we also provide local access and fiber transport services to competitive local exchange carriers.

We generate the majority of our total consolidated operating revenues from services provided in the 14-state region of Arizona, Colorado, Idaho, Iowa, Minnesota, Montana, Nebraska, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming. We refer to this region as our local service area.

On April 1, 2011, our indirect parent QCII became a wholly-owned subsidiary of CenturyLink, Inc. in a tax-free, stock-for-stock transaction.

The accompanying consolidated financial statements include our accounts and the accounts of our subsidiaries. Intercompany amounts and transactions with our consolidated subsidiaries have been eliminated. Transactions with our non-consolidated affiliates (referred to herein as affiliates) have not been eliminated.

In 2015, our ultimate parent company, CenturyLink, Inc. ("CenturyLink"), changed their allocation methodology with respect to their now centrally managed pension and post-retirement plans. Specifically, under this new methodology, CenturyLink will allocate current service costs to subsidiaries relative to employees which are currently earning benefits under the pension and post-retirement benefit plans. The net periodic benefit cost allocated to us is now paid on a monthly basis through CenturyLink’s intercompany cash management process. The change in methodology resulted in a decrease of $7 million to our net periodic benefit cost for the year ended December 31, 2015.

Changes in Estimates

As a result of our annual reviews to evaluate the reasonableness of the depreciable lives for our property, plant and equipment, effective January 2014, we changed the estimates of the remaining economic lives of certain switch and circuit network equipment. These changes resulted in an increase in depreciation expense of approximately $20 million for the year ended December 31, 2014. This increase in depreciation expense, net of tax, reduced consolidated net income by approximately $12 million for the year ended December 31, 2014.

Connect America Fund

In August of 2015, CenturyLink accepted funding from the Federal Communications Commission's ("FCC") Connect America Fund ("CAF") of approximately $500 million per year for six years to fund the deployment of voice and high-speed Internet infrastructure for approximately 1.2 million rural households and businesses in 33 states under the CAF Phase 2 high-cost support program. The funding from the CAF Phase 2 support program in these 33 states will substantially supplant funding from the interstate Universal Service Fund ("USF") high-cost program that we previously utilized to support voice services in high-cost rural markets. Of these amounts, approximately $150 million is attributable to our service area, to provide service to approximately 0.3 million rural households and businesses in 13 states. In September of 2015, we began receiving these support payments from the FCC under the new CAF Phase 2 support program, which included (i) monthly support payments at a higher rate than under the interstate USF support program and (ii) a one-time cumulative catch-up payment representing the incrementally higher funding under the CAF Phase 2 support program over the interstate USF support program for the first seven months of 2015. During 2015, we recorded $95 million more revenue than we would have otherwise recorded during the same period under the interstate USF support program.

Summary of Significant Accounting Policies

Use of Estimates

Our consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles. These accounting principles require us to make certain estimates, judgments and assumptions. We believe that the estimates, judgments and assumptions we make when accounting for specific items and matters, including, but not limited to, long-term contracts, customer retention patterns, allowance for doubtful accounts, depreciation, amortization, asset valuations, rates used for affiliate cost allocations, internal labor capitalization rates, recoverability of assets (including deferred tax assets), impairment assessments, pension, post-retirement and other post-employment benefits, taxes, certain liabilities and other provisions and contingencies, are reasonable, based on information available at the time they are made. Our accounting for CenturyLink's indirect acquisition of us required extensive use of estimates in determining the acquisition date fair values of our assets and liabilities. These estimates, judgments and assumptions can materially affect the reported amounts of assets, liabilities and components of stockholder's equity or deficit as of the dates of the consolidated balance sheets, as well as the reported amounts of revenues, expenses and components of cash flows during the periods presented in our other consolidated financial statements. We also make estimates in our assessments of potential losses in relation to threatened or pending tax and legal matters. See Note 11—Income Taxes and Note 15—Commitments and Contingencies for additional information.

For matters not related to income taxes, if a loss is considered probable and the amount can be reasonably estimated, we recognize an expense for the estimated loss. If we have the potential to recover a portion of the estimated loss from a third party, we make a separate assessment of recoverability and reduce the estimated loss if recovery is also deemed probable.

For matters related to income taxes, if we determine that the impact of an uncertain tax position is more likely than not to be sustained upon audit by the relevant taxing authority, then we recognize a benefit for the largest amount that is more likely than not to be sustained. No portion of an uncertain tax position will be recognized if the position has less than a 50% likelihood of being sustained. Interest is recognized on the amount of unrecognized benefit from uncertain tax positions.

For all of these and other matters, actual results could differ materially from our estimates.

Revenue Recognition

We recognize revenue for services when the related services are provided. Recognition of certain payments received in advance of services being provided is deferred until the service is provided. These advance payments include activation and installation charges, which we recognize as revenue over the expected customer relationship period, which ranges from eighteen months to over ten years depending on the service. We also defer costs for customer activations and installations. The deferral of customer activation and installation costs is limited to the amount of revenue deferred on advance payments. Costs in excess of advance payments are recorded as expense in the period such costs are incurred. Expected customer relationship periods are estimated using historical experience. In most cases, termination fees or other fees on existing contracts that are negotiated in conjunction with new contracts are deferred and recognized over the new contract term.

We offer bundle discounts to our customers who receive certain groupings of services. These bundle discounts are recognized concurrently with the associated revenue and are allocated to the various services in the bundled offering based on the estimated selling price of services included in each bundled combination.

Customer arrangements that include both equipment and services are evaluated to determine whether the elements are separable. If the elements are deemed separable and separate earnings processes exist, the revenue associated with the customer arrangement is allocated to each element based on the relative estimated selling price of the separate elements. We have estimated the selling prices of each element by reference to vendor-specific objective evidence of selling prices when the elements are sold separately. The revenue associated with each element is then recognized as earned. For example, if we receive an advance payment when we sell equipment and continuing service together, we immediately recognize as revenue the amount allocated to the equipment as long as all the conditions for revenue recognition have been satisfied. The portion of the advance payment allocated to the service based upon its relative selling price is recognized ratably over the longer of the contractual period or the expected customer relationship period.

We periodically transfer optical capacity assets on our network to other telecommunications service carriers. These transactions are structured as indefeasible rights of use, commonly referred to as IRUs, which are the exclusive right to use a specified amount of capacity or fiber for a specified term, typically 20 years. We account for the cash consideration received on transfers of optical capacity assets and on all of the other elements deliverable under an IRU, as revenue ratably over the term of the agreement. We have not recognized revenue on any contemporaneous exchanges of our optical capacity assets for other optical capacity assets.

In connection with offering products and services provided by third-party vendors, we review the relationship between us, the vendor and the end customer to assess whether revenue should be reported on a gross or net basis. In assessing whether revenue should be reported on a gross or net basis, we consider whether we act as a principal in the transaction, take title to the products, have risk and rewards of ownership or act as an agent or broker. Based on CenturyLink's agreements with DIRECTV and Verizon Wireless, we offer these services through sales agency relationships which are reported on a net basis.

Affiliate Transactions

We provide to our affiliates telecommunications services that we also provide to external customers. In addition, we provide to our affiliates computer system development and support services. Services provided by us to our affiliates are recognized as operating revenue-affiliates in our consolidated statements of operations. We also purchase services from our affiliates including telecommunications services, marketing and employee-related support services. Services provided to us from our affiliates are recognized as operating expenses-affiliates on our consolidated statements of operations. Because of the significance of the services we provide to our affiliates and our affiliates provide to us, the results of operations, financial position and cash flows presented herein are not necessarily indicative of the results of operations, financial position and cash flows we would have achieved had we operated as a stand-alone entity during the periods presented.

We recognize intercompany charges at the amounts billed to us by our affiliates and we recognize intercompany revenue for services we bill to our affiliates. Regulatory rules require certain revenues and expenses to be recorded at market price or fully distributed cost. Our compliance with regulations is subject to review by regulators. Adjustments to intercompany charges that result from these reviews are recorded in the period they become known.

CenturyLink has cash management arrangements between certain of its subsidiaries that include lines of credit, affiliate obligations, capital contributions and dividends. As part of these cash management arrangements, an affiliate provides lines of credit to certain other affiliates. Amounts outstanding under these lines of credit and intercompany obligations vary from time to time. Under these arrangements, the majority of our cash balance is transferred on a daily basis to CenturyLink and most affiliate transactions are deemed to be settled at the time the transactions are recorded in our accounting records, with the resulting net balance at the end of each period reflected as advances to affiliates on the accompanying consolidated balance sheets. From time to time we declare and pay dividends to our parent, QSC, which are settled through the advances to affiliates, which has the net effect of reducing the amount of these advances. Dividends declared are reflected on our consolidated statements of stockholder's equity and the consolidated statements of cash flows reflects the changes in advances to affiliates as investing activities and changes in advances from affiliates as financing activities. Interest is assessed on the advances to/from affiliates on either the three-month U.S T-bill rate (for advances to affiliates) or CenturyLink’s weighted average borrowing rate (for advances from affiliates).

The affiliates obligations, net in current and noncurrent liabilities on our consolidated balance sheets primarily represents the cumulative allocation of expense, net of payments, associated with QCII’s pension plans and post-retirement benefits plans prior to the plan mergers. In 2015, we agreed to a plan to settle the outstanding affiliate obligations, net balance with QCII over a 30 year term. Payments will be made on a monthly basis. For the year ended December 31, 2015, we made a settlement payment of $105 million to QCII on our affiliate obligations, net balance. Changes in the affiliates obligations, net are reflected in operating activities on our consolidated statements of cash flows.

In the normal course of business, we transfer assets to and from various affiliates through our parent, QSC, which are recorded through our equity. It is our policy to record asset transfers based on carrying values.

USF, Gross Receipts Taxes and Other Surcharges

In determining whether to include in our revenues and expenses the taxes and surcharges collected from customers and remitted to government authorities, including USF charges, sales, use, value added and some excise taxes, we assess, among other things, whether we are the primary obligor or principal taxpayer for the taxes assessed in each jurisdiction where we do business. In jurisdictions where we determine that we are the principal taxpayer, we record the surcharges on a gross basis and include them in our revenues and costs of services and products.

In jurisdictions where we determine that we are merely a collection agent for the government authority, we record the taxes on a net basis and do not include them in our revenues and costs of services and products.

Advertising Costs

Costs related to advertising are expensed as incurred and included in selling, general and administrative expenses in our consolidated statements of operations. Our advertising expense was $84 million, $83 million and $88 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Legal Costs

In the normal course of our business, we incur costs to hire and retain external legal counsel to advise us on regulatory, litigation and other matters. We expense these costs as the related services are received.

Income Taxes

Our results are included in the CenturyLink consolidated federal income tax return and certain combined state income tax returns. CenturyLink allocates income tax expense to us based upon a separate return allocation method which results in income tax expense that approximates the expense that would result if we were a stand-alone entity. Our reported deferred tax assets and liabilities, as discussed below and in Note 11—Income Taxes, are primarily determined as a result of the application of the separate return allocation method and therefore the settlement of these amounts is dependent upon our parent, CenturyLink, rather than tax authorities. Our current expectation is that the vast majority of deferred tax assets and liabilities will be settled through our general intercompany obligation based upon the current CenturyLink policy. CenturyLink has the right to change their policy regarding settlement of these assets and liabilities at any time.

The provision for income taxes consists of an amount for taxes currently payable, an amount for tax consequences deferred to future periods and adjustments to our liabilities for uncertain tax positions. We record deferred income tax assets and liabilities reflecting future tax consequences attributable to differences between the financial statement carrying value of assets and liabilities and the tax bases of those assets and liabilities. Deferred taxes are computed using enacted tax rates expected to apply in the year in which the differences are expected to affect taxable income. The effect on deferred income tax assets and liabilities of a change in tax rate is recognized in earnings in the period that includes the enactment date.

We establish valuation allowances when necessary to reduce deferred income tax assets to the amounts that we believe are more likely than not to be recovered. Each quarter we evaluate the need to retain all or a portion of the valuation allowance on our deferred tax assets. See Note 11—Income Taxes for additional information.

Cash and Cash Equivalents

Cash and cash equivalents include highly liquid investments that are readily convertible into cash and are not subject to significant risk from fluctuations in interest rates. As a result, the value at which cash and cash equivalents are reported in our consolidated financial statements approximates their fair value. Our cash collections are transferred to CenturyLink on a daily basis and our ultimate parent funds our cash disbursement needs. The net cash transferred to CenturyLink has been reflected as advances to affiliates in our consolidated balance sheets.

Accounts Receivable and Allowance for Doubtful Accounts

Accounts receivable are recognized based upon the amount due from customers for the services provided or at cost for purchased and other receivables less an allowance for doubtful accounts. The allowance for doubtful accounts receivable reflects our best estimate of probable losses inherent in our receivable portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other currently available evidence. We generally consider our accounts past due if they are outstanding over 30 days. Our collection process varies by the customer segment, amount of the receivable, and our evaluation of the customer's credit risk. Our past due accounts are written off against our allowance for doubtful accounts when collection is considered to be not probable. Any recoveries of accounts previously written off are generally recognized as a reduction in bad debt expense in the period received. The carrying value of accounts receivable net of the allowance for doubtful accounts approximates fair value.

Property, Plant and Equipment

As a result of our indirect acquisition by CenturyLink, property, plant and equipment acquired at the time of acquisition was recorded based on its estimated fair value as of the acquisition date. Subsequently purchased and constructed property, plant and equipment is recorded at cost. Property, plant and equipment is depreciated primarily using the straight-line group method. Under the straight-line group method, assets dedicated to providing telecommunications services (which comprise the majority of our property, plant and equipment) that have similar physical characteristics, use and expected useful lives are pooled for purposes of depreciation and tracking. The equal life group procedure is used to establish each pool's average remaining useful life. Generally, under the straight-line group method, when an asset is sold or retired in the course of normal business activities, the cost is deducted from property, plant and equipment and charged to accumulated depreciation without recognition of a gain or loss. A gain or loss is recognized in our consolidated statements of operations only if a disposal is abnormal or unusual. Leasehold improvements are amortized over the shorter of the useful lives of the assets or the expected lease term. Expenditures for maintenance and repairs are expensed as incurred. Interest is capitalized during the construction phase of network and other internal-use capital projects. Employee-related costs for construction of network and other internal use assets are also capitalized during the construction phase. Property, plant and equipment supplies used internally are carried at average cost, except for significant individual items for which cost is based on specific identification.

We perform annual internal reviews to evaluate the reasonableness of the depreciable lives for our property, plant and equipment. Our reviews utilize models that take into account actual usage, physical wear and tear, replacement history, assumptions about technology evolution and, in certain instances, actuarially determined probabilities to estimate the remaining useful life of our asset base. Our remaining useful life assessments anticipate the loss in service value of assets that may precede the physical retirement. Assets shared among many customers may lose service value as those customers leave the network. However, the asset is not retired until all customers no longer utilize the asset and we determine there is no alternative use for the asset.

We review long-lived tangible assets for impairment whenever facts and circumstances indicate that the carrying amounts of the assets may not be recoverable. For assessment purposes, long-lived assets are grouped with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities, absent a material change in operations. An impairment loss is recognized only if the carrying amount of the asset group is not recoverable and exceeds its fair value. Recoverability of the asset group to be held and used is assessed by comparing the carrying amount of the asset group to the estimated undiscounted future net cash flows expected to be generated by the asset group. If the asset group's carrying value is not recoverable, an impairment charge is recognized for the amount by which the carrying amount of the asset group exceeds its fair value. We determine fair values by using a combination of comparable market values and discounted cash flows, as appropriate.

Goodwill, Customer Relationships and Other Intangible Assets

Intangible assets arising from business combinations, such as goodwill, customer relationships and capitalized software are initially recorded at estimated fair value. We amortize customer relationships primarily over an estimated life of ten years, using either the sum-of-the-years-digits or the straight-line methods, depending on the type of customer. We amortize capitalized software using the straight-line method over estimated lives ranging up to seven years. Other intangible assets not arising from business combinations are initially recorded at cost.

Internally used software, whether purchased or developed by us, is capitalized and amortized using the straight-line method over its estimated useful life. We have capitalized certain costs associated with software such as costs of employees devoting time to the projects and external direct costs for materials and services. Costs associated with software to be used for internal purposes are expensed until the point at which the project has reached the development stage. Subsequent additions, modifications or upgrades to internal-use software are capitalized only to the extent that they allow the software to perform a task it previously did not perform. Software maintenance, data conversion and training costs are expensed in the period in which they are incurred. We review the remaining economic lives of our capitalized software annually. Capitalized software is included in other intangible assets, net, in our consolidated balance sheets.

We are required to assess goodwill for impairment at least annually, or more frequently, if an event occurs or circumstances change that would indicate an impairment may have occurred. We are required to write-down the value of goodwill in periods in which the recorded amount of goodwill exceeds the implied fair value of goodwill. The impairment assessment is performed annually at the reporting unit level. We have determined that our operations consist of one reporting unit, consistent with our determination that our business consists of one operating segment. See Note 2—Goodwill, Customer Relationships and Other Intangible Assets for additional information.

Pension and Post-Retirement Benefits

A substantial portion of our active and retired employees participate in the CenturyLink Combined Pension Plan. On December 31, 2014, the QCII pension plan and a pension plan of an affiliate were merged into the CenturyLink Retirement Plan. The CenturyLink Retirement Plan was renamed the CenturyLink Combined Pension Plan. Prior to the pension plan merger, the above-noted employees participated in the QCII pension plan. In addition, certain employees may become eligible to participate in CenturyLink's post-retirement health care and life insurance benefit plans. CenturyLink allocates service costs relating to pension and post-retirement health care and life insurance benefits to us and its other affiliates. The amounts contributed by us through CenturyLink are not segregated or restricted to pay amounts due to our employees and may be used to provide benefits to other employees of CenturyLink. The allocation of the service costs to us is based upon our employees who are currently earning benefits under the plans.

For further information on qualified pension, post-retirement and other post-employment benefit plans, see CenturyLink's Annual Report on Form 10-K for the year ended December 31, 2015.

Recently Adopted Accounting Pronouncements

In 2015, we adopted Accounting Standards Update (“ASU”) 2015-03 “Simplifying the Presentation of Debt Issuance Costs” (ASU 2015-03) and ASU 2015-17 “Balance Sheet Classification of Deferred Taxes” (ASU 2015-17). Both ASUs are intended to simplify the presentation of financial information. ASU 2015-03 requires that debt issuance costs be presented as a reduction in the associated debt rather than as an other asset, net. ASU 2015-17 requires that deferred taxes be presented on a net basis by jurisdiction as either a net noncurrent asset or liability. The ASUs affect neither the timing of expense recognition related to the debt issuance costs nor the timing of income and expense recognition related to deferred income taxes.

We adopted both ASU 2015-03 and 2015-17 by retrospectively applying the requirements of the ASUs to our previously issued consolidated financial statements. The retrospective application had no impact on our net income for the years ended December 31, 2014 and 2013, but resulted in the following changes in our previously reported consolidated balance sheet as of December 31, 2014:


•	A decrease of $163 million in Total current assets;


•	A decrease of $109 million in Other assets, net;


•	A decrease of $110 million in Long-term debt; and


•	A decrease of $162 million in Deferred income taxes, net.

The adoption of the ASUs had no impact on our net cash provided by operating activities but did change the presentation of the adjustments to reconcile net income and changes in other noncurrent assets and liabilities, net for the years ended December 31, 2014 and 2013.

Recent Accounting Pronouncements

Leases

On February 25, 2016, the FASB issued ASU 2016-02, “Leases” (“ASU 2016-02”). The core principle of ASU 2016-02 will require lessees to present right-of-use assets and lease liabilities on their balance sheets.

ASU 2016-02 is effective for annual and interim periods beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. Upon adoption of ASU 2016-02, we are required to recognize and measure leases at the beginning of the earliest period presented in our consolidated financial statements using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that we may elect to apply. We have not yet decided when we will adopt ASU 2016-02 or which practical expedient options we will elect. We are currently evaluating and assessing the impact ASU 2016-02 will have on us and our consolidated financial statements. As of the date of this Annual Report, we cannot provide any estimate of the impact of adopting ASU 2016-02.

Revenue Recognition

On May 28, 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09” or “new standard”). The new standard replaces virtually all existing generally accepted accounting principles (“GAAP”) on revenue recognition and replaces them with a principles-based approach for determining revenue recognition using a new five step model. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 also includes new accounting principles related to the deferral and amortization of contract acquisition and fulfillment costs. We currently do not defer any contract acquisition costs and defer contract fulfillment costs only up to the extent of any revenue deferred.

On July 9, 2015, the FASB approved the deferral of the effective date of ASU 2014-09 by one year until January 1, 2018. Early adoption is permitted as of January 1, 2017. ASU 2014-09 may be adopted by applying the provisions of the new standard on a retrospective basis to the periods included in the financial statements or on a modified retrospective basis which would result in the recognition of a cumulative effect of adopting ASU 2014-09 in the first quarter of 2017, if adopting early, otherwise in the first quarter of 2018. We have not yet decided which implementation method we will adopt. We are studying the new standard and are in the early stages of assessing the impact the new standard will have on us and our consolidated financial statements. We cannot at this time, however, provide any estimate of the impact of adopting the new standard.

Goodwill, Customer Relationships and Other Intangible Assets

12 Months Ended

Dec. 31, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill, Customer Relationships and Other Intangible Assets

Goodwill, customer relationships and other intangible assets consisted of the following:



	As of December 31,
	2015		2014
	(Dollars in millions)
Goodwill	$	9,354	9,354
Customer relationships, less accumulated amortization of $3,264 and $2,660	2,435		3,039
Other intangible assets subject to amortization:
Capitalized software, less accumulated amortization of $1,383 and $1,247	613		808

As of December 31, 2015, the gross carrying amount of goodwill, customer relationships and other intangible assets was $17.049 billion.

Total amortization expense for intangible assets was as follows:



	Years Ended December 31,
	2015		2014	2013
	(Dollars in millions)
Amortization expense for intangible assets	$	871	957	1,029

We estimate that total amortization expense for intangible assets for the years ending December 31, 2016 through 2020 will be as follows:



	(Dollars in millions)
Year ending December 31,
2016	$	725
2017	661
2018	587
2019	507
2020	435

We annually review the estimated lives and methods used to amortize our other intangible assets. The actual amounts of amortization expense may differ materially from our estimates, depending on the results of our annual reviews.

Our goodwill is derived from CenturyLink's acquisition of us where the purchase price exceeded the fair value of the net assets acquired.

We assess our goodwill for impairment annually, or, under certain circumstances, more frequently, such as when events or changes in circumstances indicate there may be impairment. We are required to write-down the value of goodwill only when our assessment determines the recorded amount of goodwill exceeds the fair value. Our annual impairment assessment date for goodwill is October 31, at which date we assessed goodwill at our reporting units. In reviewing the criteria for reporting units, we have determined that we are one reporting unit.

We compare our estimated fair value of equity to our carrying value of equity. If the estimated fair value of our equity is greater than the carrying value of our equity, we conclude that no impairment exists. If the estimated fair value of our equity is less than our carrying value of our equity, a second calculation is required in which the implied fair value of goodwill is compared to our carrying value of goodwill. If the implied fair value of goodwill is less than our carrying value of goodwill, goodwill must be written down to the implied fair value.

At October 31, 2015, we estimated the fair value of our equity by considering both a market approach and a discounted cash flow method, which resulted in a Level 3 fair value measurement. The market approach method includes the use of comparable multiples of publicly traded companies whose services are comparable to ours. The discounted cash flow method is based on the present value of projected cash flows and a terminal value, which represents the expected normalized cash flows of the reporting unit beyond the cash flows from the discrete projection period. We discounted the estimated cash flows using a rate that represents our estimated weighted average cost of capital, which we determined to be approximately 6.0% as of the assessment date (which was comprised of an after-tax cost of debt of 3.3% and a cost of equity of 7.6%). Based on our assessment performed with respect to our reporting unit as described above, we concluded that our goodwill was not impaired as of that date.

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Long-Term Debt and Revolving Promissory Note

12 Months Ended

Dec. 31, 2015

Debt Disclosure [Abstract]

Long-Term Debt and Revolving Promissory Note

Long-term debt, including unamortized premiums and discounts, unamortized debt issuance costs and note payable-affiliate, were as follows:



			As of December 31,
	Interest Rates	Maturities	2015			2014
			(Dollars in millions)
Senior notes	6.125% - 8.375%	2016 - 2055	$	7,229		7,311
Term loan	2.180%	2025	100			—
Capital lease and other obligations	Various	Various	17			32
Unamortized premiums, net			16			36
Unamortized debt issuance costs			(123		)	(110	)
Total long-term debt			7,239			7,269
Less current maturities			(242		)	(117	)
Long-term debt, excluding current maturities			$	6,997		7,152
Note payable-affiliate	6.758%	2022	$	855		796

New Issuances

2015

On September 21, 2015, we issued $400 million aggregate principal amount of 6.625% Notes due 2055, in exchange for net proceeds, after deducting underwriting discounts and other expenses, of approximately $386 million. The underwriting agreement included an over-allotment option granting the underwriters for the offering an opportunity to purchase additional 6.625% Notes due 2055. On September 30, 2015, we issued an additional $10 million aggregate principal amount of the 6.625% Notes under this over-allotment option. All of the 6.625% Notes are unsecured obligations and may be redeemed by us, in whole or in part, on or after September 15, 2020, at a redemption price equal to 100% of the principal amount redeemed plus accrued and unpaid interest to the redemption date.

2014

On September 29, 2014, we issued $500 million aggregate principal amount of 6.875% Notes due 2054, in exchange for net proceeds, after deducting underwriting discounts and other expenses, of $483 million. The Notes are senior unsecured obligations and may be redeemed, in whole or in part, on or after October 1, 2019, at a redemption price equal to 100% of the principal amount redeemed plus accrued and unpaid interest to the redemption date.

Repayments

2015

On October 13, 2015, we redeemed all $250 million of our 7.20% Notes due 2026, which resulted in an immaterial gain, and redeemed $150 million of our 6.875% Notes due 2033, which resulted in an immaterial loss.

On June 15, 2015, we paid at maturity the $92 million principal amount of our 7.625% Notes.

2014

On October 1, 2014, we paid at maturity the $600 million principal amount of our 7.50% Notes.

Term Loan

On February 20, 2015, we entered into a term loan in the amount of $100 million with CoBank, ACB. The outstanding unpaid principal amount of this term loan plus any accrued and unpaid interest is due on February 20, 2025. Interest is paid monthly based upon either the London Interbank Offered Rate (“LIBOR”) or the base rate (as defined in the credit agreement) plus an applicable margin between 1.50% to 2.50% per annum for LIBOR loans and 0.50% to 1.50% per annum for base rate loans depending on our then current senior unsecured long-term debt rating. At December 31, 2015, the outstanding principal balance on this term loan was $100 million.

Aggregate Maturities of Long-Term Debt

Set forth below is the aggregate principal amount of our long-term debt (excluding unamortized premiums and discounts, net and unamortized debt issuance costs and other and excluding note payable-affiliate) maturing during the following years:



	(Dollars in millions)⁽¹⁾
2016	$	242
2017	503
2018	3
2019	1
2020	—
2021 and thereafter	6,597
Total long-term debt	$	7,346

_______________________________________________________________________________

⁽¹⁾Actual principal paid in all years may differ due to the possible future refinancing of outstanding debt or the issuance of new debt.

Revolving Promissory Note

We are currently indebted to an affiliate of our ultimate parent company, CenturyLink, under a revolving promissory note that provides us with a funding commitment of up to $1.0 billion aggregate principal amount through June 30, 2022, of which $855 million was outstanding as of December 31, 2015. As of December 31, 2015, the weighted average interest rate was 6.758%. As of December 31, 2015 and 2014, this revolving promissory note is reflected on our consolidated balance sheets as a current liability under “Note payable-affiliate”. As of December 31, 2015, $5 million of accrued interest is reflected in other current liabilities on our consolidated balance sheet. In accordance with the note agreement, all accrued and unpaid interest is capitalized to the unpaid principal balance on June 1 and December 1 of each year.

Interest Expense

Interest expense includes interest on long-term debt. The following table presents the amount of gross interest expense, net of capitalized interest and interest expense-affiliates, net:



	Years Ended December 31,
	2015			2014		2013
	(Dollars in millions)
Interest expense:
Gross interest expense	$	491		481		467
Capitalized interest	(18		)	(17	)	(17	)
Total interest expense	$	473		464		450
Interest expense-affiliates, net	$	53		40		64

Covenants

The indentures governing our notes contain certain covenants including, but not limited to: (i) a prohibition on certain liens on our assets; and (ii) a limitation on mergers or sales of all, or substantially all, of our assets, which limitation requires that a successor assume the obligation with regard to these notes. These indentures do not contain any cross-default provisions.

Our senior notes were issued under indentures dated April 15, 1990 and October 15, 1999. These indentures restrict our ability to (i) incur, issue or create liens upon our property and (ii) consolidate with or merge into, or transfer or lease all or substantially all of our assets to any other party.

At December 31, 2015, we believe we were in compliance with all of the provisions and covenants contained in our debt agreements.

Subsequent Event

In January 2016, we issued $235 million aggregate principal amount of 7% Notes due 2056, in exchange for net proceeds, after deducting underwriting discounts and other expenses, of approximately $227 million. All of the 7% Notes are unsecured obligations and may be redeemed by us, in whole or in part, on or after February 1, 2021, at a redemption price equal to 100% of the principal amount redeemed plus accrued and unpaid interest to the redemption date.

Accounts Receivable

12 Months Ended

Dec. 31, 2015

Receivables [Abstract]

Accounts Receivable

The following table presents details of our accounts receivable balances:



	As of December 31,
	2015			2014
	(Dollars in millions)
Trade and purchased receivables	$	620		649
Earned and unbilled receivables	111			120
Other	4			9
Total accounts receivable	735			778
Less: allowance for doubtful accounts	(47		)	(38	)
Accounts receivable, less allowance	$	688		740

We are exposed to concentrations of credit risk from residential and business customers within our local service area and from other telecommunications service providers. No customers individually represented more than 10% of our accounts receivable for all periods presented herein. We generally do not require collateral to secure our receivable balances. We have agreements with other telecommunications service providers whereby we agree to bill and collect on their behalf for services rendered by those providers to our customers within our local service area. We purchase accounts receivable from other telecommunications service providers primarily on a recourse basis and include these amounts in our accounts receivable balance. We have not experienced any significant loss associated with these purchased receivables.

The following table presents details of our allowance for doubtful accounts:



	Beginning Balance		Additions	Deductions		Ending Balance
	(Dollars in millions)
2015	$	38	78	(69	)	47
2014	$	43	64	(69	)	38
2013	$	46	65	(68	)	43

Property, Plant and Equipment

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Net property, plant and equipment is composed of the following:



	Depreciable Lives	As of December 31,
	Depreciable Lives	2015			2014
		(Dollars in millions)
Property, plant and equipment:
Land	N/A	$	349		350
Fiber, conduit and other outside plant⁽¹⁾	15-45 years	5,362			4,640
Central office and other network electronics⁽²⁾	4-10 years	3,614			3,362
Support assets⁽³⁾	5-30 years	2,584			2,496
Construction in progress⁽⁴⁾	N/A	273			309
Gross property, plant and equipment		12,182			11,157
Accumulated depreciation		(4,808		)	(3,956	)
Net property, plant and equipment		$	7,374		7,201

_______________________________________________________________________________


⁽¹⁾	Fiber, conduit and other outside plant consists of fiber and metallic cable, conduit, poles and other supporting structures.


⁽²⁾	Central office and other network electronics consists of circuit and packet switches, routers, transmission electronics and electronics providing service to customers.


⁽³⁾	Support assets consist of buildings, computers and other administrative and support equipment.


⁽⁴⁾	Construction in progress includes inventory held for construction and property of the aforementioned categories that has not been placed in service as it is still under construction.

We recorded depreciation expense of $986 million, $1.048 billion and $1.099 billion for the years ended December 31, 2015, 2014 and 2013, respectively.

In 2014, we recorded an impairment charge of $17 million in connection with a sale-leaseback transaction involving an office building which closed in the fourth quarter of 2014. This impairment charge is included in selling, general and administrative expense in our consolidated statement of operations for the year ended December 31, 2014.

Severance

12 Months Ended

Dec. 31, 2015

Restructuring and Related Activities [Abstract]

Severance

Periodically, we have reductions in our workforce and have accrued liabilities for the related severance costs. These workforce reductions resulted primarily from the progression or completion of our post-acquisition integration plans related to CenturyLink's indirect acquisition of us, increased competitive pressures, cost reduction initiatives and reduced workload demands due to the loss of customers purchasing certain legacy services.

We report severance liabilities within accrued expenses and other liabilities-salaries and benefits in our consolidated balance sheets and report severance expenses in cost of services and products and selling, general and administrative expenses in our consolidated statements of operations.

Changes in our accrued liability for severance expenses were as follows:



	Severance
	(Dollars in millions)
Balance at December 31, 2013	$	5
Accrued to expense	44
Payments, net	(39		)
Balance at December 31, 2014	$	10
Accrued to expense	51
Payments, net	(55		)
Balance at December 31, 2015	$	6

Employee Benefits	12 Months Ended
Employee Benefits	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefits	Employee Benefits Pension and Post-Retirement Benefits We are required to disclose the amount of our contributions to CenturyLink relative to the CenturyLink qualified pension plans and post-retirement benefit plans and the amount of income or expense from these plans allocated by CenturyLink to us and their other affiliates. QCII's post-retirement benefit plans were merged into CenturyLink's post-retirement benefit plans on January 1, 2012 and on December 31, 2014, QCII's qualified pension plan and a pension plan of an affiliate were merged into the CenturyLink Retirement Plan, which was renamed the CenturyLink Combined Pension Plan. Prior to the plan mergers, a substantial portion of our active and retired employees participated in QCII's pension and post-retirement plans. Based on current laws and circumstances, (i) CenturyLink was not required to make a cash contribution to the CenturyLink Combined Pension Plan in 2015 and (ii) CenturyLink does not expect it will be required to make a contribution in 2016. The amount of required contributions to the CenturyLink Combined Pension Plan in 2017 and beyond will depend on earnings on plan investments, prevailing discount rates, demographic experience, changes in plan benefits and changes in funding laws and regulations. CenturyLink occasionally makes voluntary contributions in addition to required contributions, and CenturyLink made such a voluntary cash contribution of $100 million to the CenturyLink Combined Pension Plan during the third quarter of 2015. No contributions were made to the post-retirement occupational health care trust in 2015 or 2014 and CenturyLink does not expect to make a contribution in 2016. The unfunded status of CenturyLink's qualified pension plan for accounting purposes was $2.207 billion and $2.402 billion as of December 31, 2015 and 2014, respectively, which includes the merged QCII qualified pension plan. The unfunded status of CenturyLink's post-retirement benefit plans for accounting purposes was $3.374 billion and $3.477 billion as of December 31, 2015 and 2014, respectively. In 2015, our ultimate parent company, CenturyLink, changed their allocation methodology with respect to their now centrally managed pension and post-retirement plans. Specifically, under this new methodology, CenturyLink will allocate current service costs to subsidiaries relative to employees which are currently earning benefits under the pension and post-retirement benefit plans. The net periodic benefit cost allocated to us is now paid on a monthly basis through CenturyLink’s intercompany cash management process. The change in methodology resulted in a decrease of $7 million to our net periodic benefit cost for the year ended December 31, 2015. The affiliates obligations, net in current and noncurrent liabilities on the consolidated balance sheets primarily represents the cumulative allocation of expense, net of payments, associated with QCII's pension plans and post-retirement benefits plans prior to the plan mergers. In 2015, we agreed to a plan to settle the outstanding pension and post-retirement affiliate obligations, net balance with QCII over a 30 year term. Payments will be made on a monthly basis. For the year ended December 31, 2015, we made a settlement payment of $105 million to QCII on our affiliate obligations, net balance. Changes in the affiliates obligations, net are reflected in operating activities on our consolidated statements of cash flows. We were allocated $57 million of pension service costs and $17 million of post-retirement service costs during the year ended December 31, 2015, which represented 69% of CenturyLink's total pension and post-retirement service costs for the year. The combined net pension and post-retirement service costs is included in cost of services and products and selling, general and administrative expenses on our consolidated statement of operations for the year ended December 31, 2015. We were allocated $98 million and $178 million in pension income during the years ended December 31, 2014 and 2013, respectively. Our allocated post-retirement benefit expense for the years ended December 31, 2014 and 2013 was $128 million and $88 million, respectively. These allocated amounts represent our share of the pension and post-retirement benefit expenses based on the actuarially determined amounts. Prior to the plan mergers, our allocated portion of QCII's pension and post-retirement benefit income and expense was 92% and 91% for the years ended December 31, 2014 and 2013, respectively. The combined net pension and post-retirement benefits (income) expenses is included in cost of services and products and selling, general and administrative expenses on our consolidated statements of operations for the years ended December 31, 2014 and 2013. CenturyLink sponsors a noncontributory qualified defined benefit pension plan that covers substantially all of our employees. As noted above, on December 31, 2014, QCII's pension plan was merged into the CenturyLink Retirement Plan, which was renamed the CenturyLink Combined Pension Plan. The plan also provides survivor and disability benefits to certain employees. In November 2009, and prior to the plan merger, the pension plan was amended to no longer provide pension benefit accruals for active non-represented employees after December 31, 2009. In addition, non-represented employees hired after January 1, 2009 are not eligible to participate in the plans. Active non-represented employees who participate in these plans retain their accrued pension benefit earned as of December 31, 2009 and certain participants will continue to earn interest credits on their benefit after December 31, 2009. Employees are eligible to receive their vested accrued benefit when they separate from CenturyLink. The plans also provided a death benefit for eligible beneficiaries of certain retirees; however, the plan was amended to eliminate this benefit effective March 1, 2010 for retirees who retired prior to January 1, 2004 and whose deaths occur after February 28, 2010 and eliminate the death benefit for eligible beneficiaries of certain retirees who retired after December 31, 2003. CenturyLink maintains post-retirement benefit plans that provide health care and life insurance benefits for certain eligible retirees. The QCII post-retirement benefit plans were merged into CenturyLink's post-retirement benefit plans on January 1, 2012. The benefit obligation for the occupational health care and life insurance post-retirement plans is estimated based on the terms of benefit plans. In calculating this obligation, CenturyLink considers numerous assumptions, estimates and judgments, including but not limited to, discount rates, health care cost trend rates and plan amendments. In October 2013, we renewed a four-year collective bargaining agreement which covers approximately 11,000 of our unionized employees. Effective January 1, 2014, the approximately 11,000 active employees and eligible post-1990 retirees who are former represented employees, have changes to their health and welfare benefits including: (i) changes to align the coverage and benefits for these active employees and non-Medicare eligible post-1990 retirees with the health and welfare coverage and benefits offered to all other CenturyLink employees and other CenturyLink retirees (with some exceptions) (ii) increased out-of-pocket health care costs through plan design changes effective January 1, 2014 and the elimination of Class II dependent coverage and (iii) elimination of the group medical plan coverage and benefits for Medicare-eligible post-1990 retirees and the establishment of a health reimbursement account and assistance to this population with their transition effective May 1, 2014 to their own purchase of individual policies through the Medicare Exchange market place using the health reimbursement account. In order to maintain their eligibility, post-1990 retirees continue to be obligated to contribute to the cost of health care benefits in excess of specified limits on the company-funded portion of retiree health care costs (also referred to as the "caps"), as they have since January 1, 2009. The terms of the post-retirement health care and life insurance plans between CenturyLink and its eligible non-represented employees and its eligible post-1990 non-represented retirees are established by CenturyLink and are subject to change at its discretion. CenturyLink has a practice of sharing some of the cost of providing health care benefits with its non-represented employees and post-1990 non-represented retirees. The benefit obligation for the non-represented post-retirement health care benefits is based on the terms of the current written plan documents and is adjusted for anticipated continued cost sharing with non-represented employees and post-1990 non-represented retirees. However, CenturyLink's contribution under its post-1990 non-represented retirees' health care plan is capped at a specific dollar amount. Medicare Prescription Drug, Improvement and Modernization Act of 2003 CenturyLink sponsors post-retirement health care plans with several benefit options that provide prescription drug benefits that CenturyLink deems actuarially equivalent to or exceeding Medicare Part D. CenturyLink recognizes the impact of the federal subsidy received under the Medicare Prescription Drug, Improvement and Modernization Act of 2003 in the calculation of its post-retirement benefit obligation and net periodic post-retirement benefit expense. Other Benefit Plans Health Care and Life Insurance We provide health care and life insurance benefits to essentially all of our active employees. We are largely self-funded for the cost of the health care plan. Our health care benefit expense for current employees was $217 million, $204 million and $223 million for the years ended December 31, 2015, 2014 and 2013, respectively. Union-represented employee benefits are based on negotiated collective bargaining agreements. Employees' group basic life insurance plans are fully insured and the premiums are paid by CenturyLink. 401(k) Plan CenturyLink sponsors qualified defined contribution plans covering substantially all of our employees. Under these plans, employees may contribute a percentage of their annual compensation up to certain maximums, as defined by the plans and by the Internal Revenue Service ("IRS"). Currently, we match a percentage of our employees' contributions in cash. We recognized $43 million, $47 million and $49 million in expense related to these plans for the years ended December 31, 2015, 2014 and 2013, respectively. Deferred Compensation Plans CenturyLink sponsors non-qualified unfunded deferred compensation plans for various groups that includes certain of our current and former highly compensated employees. The plans are frozen and participants can no longer defer compensation to these plans. The value of the assets and liabilities related to these plans is not significant.

Share-Based Compensation	12 Months Ended
Share-Based Compensation	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-based Compensation Share-based compensation expenses are included in cost of services and products, and selling, general, and administrative expenses in our consolidated statements of operations. We recognized compensation expense for options and awards granted to our employees under CenturyLink's equity incentive plans, including plans assumed in connection with us being indirectly acquired. We record share-based compensation expense that is allocated to us from CenturyLink, which is included in operating expenses-affiliates in our consolidated statements of operations. Based on many factors that affect the allocation, the amount of share-based compensation expense recorded at CenturyLink and ultimately allocated to us may fluctuate. We settle the share-based compensation expense allocated to us from CenturyLink through affiliate transactions. For the years ended December 31, 2015, 2014 and 2013, we were allocated a share-based compensation expense of approximately $21 million, $21 million and $17 million, respectively. We recognized an income tax benefit from our compensation expense of approximately $8 million, $8 million and $7 million, respectively, during the years ended December 31, 2015, 2014 and 2013, respectively.

Products and Services Revenues

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Products and Services Revenues

We are an integrated communications company engaged primarily in providing an array of communications services, including local voice, high-speed Internet, private line (including special access), network access, Ethernet, information technology, video, wireless and other ancillary services. We strive to maintain our customer relationships by, among other things, bundling our service offerings to provide our customers with a complete offering of integrated communications services. We currently categorize our products, services and revenues among the following three categories:


•	Strategic services, which include primarily high-speed Internet, private line (including special access), Ethernet, Verizon Wireless and other ancillary services;


•	Legacy services, which include primarily local voice, Integrated Services Digital Network ("ISDN") services (which use regular telephone lines to support voice, video and data applications), switched access and traditional wide area network ("WAN") services (which allow a local communications network to link to networks in remote locations); and

•

Affiliates and other services, which consist primarily of CAF support payments, USF support payments, USF surcharges and services we provide to our affiliates. We receive federal support payments from both CAF Phase 1 and CAF Phase 2 programs, and support payments from both federal and state USF programs. These support payments are government subsidies designed to reimburse us for various costs related to certain telecommunications services, including the costs of deploying, maintaining and operating voice and high-speed Internet infrastructure in high-cost rural areas where we are not able to recover our costs from our customers. USF surcharges are the amounts we collect based on specific items we list on our customers' invoices to fund the FCC's universal service programs. We provide to our affiliates, telecommunication services that we also provide to external customers. In addition, we provide to our affiliates, computer system development and support services, network support and technical services.

Our operating revenues for our products and services consisted of the following categories for the years ended December 31, 2015, 2014 and 2013:



	Years Ended December 31,
	2015		2014	2013
	(Dollars in millions)
Strategic services	$	3,433	3,429	3,342
Legacy services	2,777		2,987	3,208
Affiliates and other services	2,754		2,422	2,203
Total operating revenues	$	8,964	8,838	8,753

We do not have any single external customer that provides more than 10% of our total consolidated operating revenues. Substantially all of our consolidated revenues come from customers located in the United States.

We recognize revenues in our consolidated statements of operations for certain USF surcharges and transaction taxes that we bill to our customers. Our consolidated statements of operations also reflect the related expense for the amounts we remit to the government agencies. The total amount of such surcharges that we included in revenues, aggregated approximately $147 million, $151 million and $154 million for the years ended December 31, 2015, 2014 and 2013, respectively. Those USF surcharges, where we record revenue, are included in "other" operating revenues and transaction tax surcharges are included in "legacy services" revenues. We also act as a collection agent for certain other USF and transaction taxes that we are required by government agencies to include in our bills to customers, for which we do not record any revenue or expense because we only act as a pass-through agent.

Our operations are integrated into and reported as part of the consolidated segment data of CenturyLink. CenturyLink's chief operating decision maker ("CODM") is our CODM, but reviews our financial information on an aggregate basis only in connection with our quarterly and annual reports that we file with the Securities and Exchange Commission. Consequently, we do not provide our discrete financial information to the CODM on a regular basis. As such, we believe we have one reportable segment.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8981-108599

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e9038-108599

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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+ Details

Affiliate Transactions

12 Months Ended

Dec. 31, 2015

Affiliate Transactions

We provide to our affiliates, telecommunications services that we also provide to external customers. In addition, we provide to our affiliates, computer system development and support services and network support and technical services.

Below are details of the services we provide to our affiliates:


•	Telecommunications services. Data, Internet and voice services in support of our affiliates' service offerings;

•

Computer system development and support services. Information technology services primarily include the labor cost of developing, testing and implementing the system changes necessary to support order entry, provisioning, billing, network and financial systems, as well as the cost of improving, maintaining and operating our operations support systems and shared internal communications networks; and


•	Network support and technical services. Network support and technical services relate to forecasting demand volumes and developing plans around network utilization and optimization, developing and implementing plans for overall product development, provisioning and customer care.

We charge our affiliates for services based on market price or fully distributed cost ("FDC"). We charge our affiliates market price for services that we also provide to external customers, while other services that we provide only to our affiliates are priced by applying an FDC methodology. FDC rates include salaries and wages, payroll taxes, employee related benefits, miscellaneous expenses, and charges for the use of our buildings, computing and software assets. Whenever possible, costs are directly assigned to our affiliates for the services they use. If costs cannot be directly assigned, they are allocated among all affiliates based upon cost causative measures; or if no cost causative measure is available, these costs are allocated based on a general allocator. These cost allocation methodologies are reasonable. From time to time, we adjust the basis for allocating the costs of a shared service among affiliates. Such changes in allocation methodologies are generally billed prospectively.

We also purchase services from our affiliates including telecommunication services, insurance, flight services and other support services such as legal, regulatory, finance and accounting, tax, human resources and executive support. Our affiliates charge us for these services based on market price or FDC.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References + Details

Income Taxes

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Income Taxes

We were included in the consolidated federal income tax returns and the combined state income tax returns of QCII until CenturyLink's April 1, 2011 acquisition of QCII and the consolidated federal income tax returns and certain combined state income tax returns of CenturyLink subsequent to the acquisition. Both CenturyLink and QCII treat our consolidated results as if we were a separate taxpayer. The policy requires us to settle our tax liabilities through a change in our general intercompany obligation based upon our separate return taxable income, which is reflected in advances to affiliates on our consolidated balance sheets and the changes in advances to affiliates are reflected as investing activities on our consolidated statements of cash flows. Because we are included in the consolidated federal income tax returns and the combined state income tax returns of CenturyLink (and previously with QCII), any tax audits involving CenturyLink or QCII will also involve us. The IRS previously examined all of QCII's federal income tax returns prior to 2008 because they were included in its coordinated industry case program and now examines all of QCII's federal income tax returns as included in the consolidated federal return of the ultimate parent company, CenturyLink.

In 2013, CenturyLink filed an amended 2009 consolidated federal income tax return primarily to report the carryforward impact of prior year settlements. The refund for the 2009 amended return filed in 2013 was received in 2014. In 2014, CenturyLink filed an amended consolidated federal income tax return for 2010. The refund claim filed for 2010 was accepted by the IRS, and the refund was received in 2015. The 2010 amended return released certain general business credits that were required to be carried back to 2009. As a result, a subsequent 2009 federal amended return was filed in 2014 to reflect the carrybacks from 2010. The 2009 refund claim filed in 2014 was accepted by the IRS and the refund was received in 2015. Beginning with the 2012 tax year, CenturyLink's federal consolidated returns are subject to annual examination by the IRS.

Our open income tax years by major jurisdiction are as follows at December 31, 2015:



Jurisdiction		Open Tax Years
Federal		2012—current
State
Arizona		2010—current
Florida		2010—current
Other states		2011—current

Since the period for assessing additional liability typically begins upon the filing of a return, it is possible that certain jurisdictions could assess tax for years prior to the open tax years disclosed above. Additionally, it is possible that certain jurisdictions in which we do not believe we have an income tax filing responsibility, and accordingly did not file a return, may attempt to assess a liability, or other jurisdictions to which we pay taxes may attempt to assert that we owe additional taxes.

As of December 31, 2015, 2014, and 2013, we had no liability for interest related to uncertain tax positions. We did not record a liability for interest related to uncertain tax positions for the year ended December 31, 2015. We made no accrual for penalties related to income tax positions.

Income Tax Expense

The components of the income tax expense from continuing operations are as follows:



	Years Ended December 31,
	2015			2014		2013
	(Dollars in millions)
Income tax expense:
Current tax provision:
Federal and foreign	$	734		738		653
State and local	114			129		101
Total current tax provision	848			867		754
Deferred tax expense:
Federal and foreign	(170		)	(209	)	(125	)
State and local	(19		)	(19	)	(27	)
Total deferred tax expense	(189		)	(228	)	(152	)
Income tax expense	$	659		639		602

The effective income tax rate for continuing operations differs from the statutory tax rate as follows:



	Years Ended December 31,
	2015		2014		2013
	(in percent)
Effective income tax rate:
Federal statutory income tax rate	35.0	%	35.0	%	35.0	%
State income taxes-net of federal effect	3.6	%	4.0	%	3.1	%
Other	(0.6	)%	0.7	%	0.3	%
Effective income tax rate	38.0	%	39.7	%	38.4	%

Deferred Tax Assets and Liabilities

The components of the deferred tax assets and liabilities are as follows:



	As of December 31,
	2015			2014
	(Dollars in millions)
Deferred tax assets and liabilities:
Deferred tax liabilities:
Property, plant and equipment	$	(1,431	)	(1,380	)
Intangibles assets	(1,153		)	(1,449	)
Receivable from an affiliate due to pension plan participation	(460		)	(500	)
Other	(59		)	(52	)
Total deferred tax liabilities	(3,103		)	(3,381	)
Deferred tax assets:
Payable to affiliate due to post-retirement benefit plan participation	921			998
Debt premiums	21			36
Other	277			274
Total deferred tax assets	1,219			1,308
Valuation allowance on deferred tax assets	(12		)	(12	)
Net deferred tax assets	1,207			1,296
Net deferred tax liabilities	$	(1,896	)	(2,085	)

At December 31, 2015, we have established a valuation allowance of $12 million as it is not more likely than not that this amount of deferred tax assets will be realized.

Other Income Tax Information

We paid $848 million, $861 million and $750 million to QSC related to income taxes in the years ended December 31, 2015, 2014 and 2013, respectively.

Fair Value Disclosure

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Fair Value Disclosure

Our financial instruments consist of cash and cash equivalents, accounts receivable, advances to affiliates, accounts payable, note payable-affiliate and long-term debt excluding capital lease obligations. Due to their short-term nature, the carrying amounts of our cash and cash equivalents, accounts receivable, advances to affiliates, accounts payable and note payable-affiliate approximate their fair values.

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between independent and knowledgeable parties who are willing and able to transact for an asset or liability at the measurement date. We use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs when determining fair value and then we rank the estimated values based on the reliability of the inputs used following the fair value hierarchy set forth by the FASB. We determined the fair values of our long-term debt, including the current portion, based on quoted market prices where available or, if not available, based on discounted future cash flows using current market interest rates.

The three input levels in the hierarchy of fair value measurements are defined by the FASB generally as follows:



Input Level		Description of Input
Level 1		Observable inputs such as quoted market prices in active markets.
Level 2		Inputs other than quoted prices in active markets that are either directly or indirectly observable.
Level 3		Unobservable inputs in which little or no market data exists.

The following table presents the carrying amounts and estimated fair values of our long-term debt, excluding capital lease and other obligations and unamortized debt issuance costs, as well as the input levels used to determine the fair values:



		As of December 31, 2015			As of December 31, 2014
	Input Level	Carrying Amount		Fair Value	Carrying Amount	Fair Value
		(Dollars in millions)
Liabilities-Long-term debt (excluding capital lease and other obligations)	2	$	7,222	7,456	7,237	7,702

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Stockholder's Equity

12 Months Ended

Dec. 31, 2015

Stockholders' Equity Note [Abstract]

Stockholder's Equity

Common Stock

We have one share of common stock (no par value) issued and outstanding, which is owned by QSC.

In addition, in the normal course of business, we transfer assets and liabilities to and from QSC and its affiliates, which are recorded through our equity. It is our policy to record these asset transfers based on carrying values.

Dividends

We declared the following cash dividend to QSC:



	Years Ended December 31,
	2015		2014	2013
	(Dollars in millions)
Cash dividend declared to QSC	$	1,350	1,400	1,325
Cash dividend paid to QSC	1,350		1,400	1,325

The timing of cash payments for declared dividends to QSC is at our discretion in consultation with QSC. We may declare and pay dividends to QSC in excess of our earnings to the extent permitted by applicable law. Our debt covenants do not limit the amount of dividends we can pay to QSC.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

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Reference 15: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Quarterly Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Data (Unaudited)



	First Quarter		Second Quarter	Third Quarter	Fourth Quarter	Total
	(Dollars in millions)
2015
Operating revenues	$	2,217	2,222	2,287	2,238	8,964
Operating income	545		521	572	622	2,260
Income tax expense	167		152	171	169	659
Net income	247		238	268	321	1,074



	First Quarter		Second Quarter	Third Quarter	Fourth Quarter	Total
	(Dollars in millions)
2014
Operating revenues	$	2,211	2,206	2,198	2,223	8,838
Operating income	542		546	528	496	2,112
Income tax expense	160		162	156	161	639
Net income	253		256	245	216	970

During the third quarter of 2015, we recognized an incremental $64 million of revenue associated with the FCC's CAF Phase 2 support program, and an additional incremental $31 million in the fourth quarter of 2015.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Legal Matters

From time to time, we are involved in other proceedings incidental to our business, including patent infringement allegations, administrative hearings of state public utility commissions relating primarily to our rates or services, actions relating to employee claims, various tax issues, environmental law issues, grievance hearings before labor regulatory agencies and miscellaneous third party tort actions.

We are currently defending several patent infringement lawsuits asserted against us by non-practicing entities, many of whom are seeking substantial recoveries. These cases have progressed to various stages and one or more may go to trial in the coming 24 months if they are not otherwise resolved. Where applicable, we are seeking full or partial indemnification from our vendors and suppliers. As with all litigation, we are vigorously defending these actions and, as a matter of course, we are prepared both to litigate these matters to judgment, as well as to evaluate and consider all reasonable settlement opportunities.

We are among hundreds of defendants nationwide in dozens of lawsuits filed by Sprint Communications Company and affiliates of Verizon Communications Inc. The plaintiffs in these suits have challenged the right of local exchange carriers to bill interexchange carriers for switched access charges for certain calls between mobile and wireline devices that are routed through an interexchange carrier. In the lawsuits, the plaintiffs are seeking refunds of access charges previously paid and relief from future access charges. In addition, these and some other interexchange carriers have ceased paying switched access charges on these calls. These lawsuits involving us and many other carriers have been consolidated for pretrial purposes in the United States District Court for the District of Northern Texas. In November 2015, the Court dismissed the plaintiffs' federal law claims and granted them leave to file state law claims, if any. Some of the defendants, including us, have petitioned the Federal Communications Commission to address these issues on an industry-wide basis.

The outcome of these disputes and suits, as well as any related regulatory proceedings that could ensue, are currently not predictable. If we are required to stop assessing these charges or to pay refunds of any such charges, our financial results could be negatively affected.

CenturyLink and its affiliates are involved in several legal proceedings to which we are not a party that, if resolved against them, could have a material adverse effect on their business and financial condition. As an indirect wholly-owned subsidiary of CenturyLink, our business and financial condition could be similarly affected. You can find descriptions of these legal proceedings in CenturyLink's quarterly and annual reports filed with the Securities and Exchange Commission. Because we are not a party to any of the matters, we have not accrued any liabilities for the matters.

We are subject to various federal, state and local environmental protection and health and safety laws. From time to time, we are subject to judicial and administrative proceedings brought by various governmental authorities under these laws. Several such proceedings are currently pending, but none is reasonably expected to exceed $100,000 in fines and penalties.

The outcome of these other proceedings is not predictable. However, based on current circumstances, we do not believe that the ultimate resolution of these other proceedings, after considering available defenses and any insurance coverage or indemnification rights, will have a material adverse effect on our financial position, results of operations or cash flows.

Capital Leases

We lease certain facilities and equipment under various capital lease arrangements. Depreciation of assets under capital leases is included in depreciation and amortization expense in our consolidated statements of operations. Payments on capital leases are included in repayments of long-term debt, including current maturities in our consolidated statements of cash flows.

The tables below summarize our capital lease activity:



	Years Ended December 31,
	2015		2014	2013
	(Dollars in millions)
Assets acquired through capital leases	$	10	3	—
Depreciation expense	19		32	42
Cash payments towards capital leases	20		32	40



	As of December 31,
	2015		2014
	(Dollars in millions)
Assets included in property, plant and equipment	$	66	137
Accumulated depreciation	55		108

The future annual minimum payments under capital lease arrangements as of December 31, 2015 were as follows:



	Future Minimum Payments
	(Dollars in millions)
Capital lease obligations:
2016	$	8
2017	4
2018	4
2019	2
2020	—
2021 and thereafter	5
Total minimum payments	23
Less: amount representing interest and executory costs	(7		)
Present value of minimum payments	16
Less: current portion	(6		)
Long-term portion	$	10

Operating Leases

We lease various equipment, office facilities, retail outlets, switching facilities and other network sites. These leases, with few exceptions, provide for renewal options and escalations that are either fixed or based on the consumer price index. Any rent abatements, along with rent escalations, are included in the computation of rent expense calculated on a straight-line basis over the lease term. The lease term for most leases includes the initial non-cancelable term plus any term under renewal options that are reasonably assured. For the years ended December 31, 2015, 2014 and 2013, our gross rental expense was $75 million, $79 million and $83 million, respectively. We also received sublease rental income for the years ended December 31, 2015, 2014 and 2013 of $4 million, $4 million and $4 million, respectively.

At December 31, 2015, our future rental commitments for operating leases were as follows:



	Future Minimum Payments
	(Dollars in millions)
Operating leases:
2016	$	56
2017	50
2018	45
2019	37
2020	32
2021 and thereafter	52
Total future minimum payments⁽¹⁾	$	272

_______________________________________________________________________________


⁽¹⁾	Minimum payments have not been reduced by minimum sublease rentals of $30 million due in the future under non-cancelable subleases.

Purchase Commitments

We have several commitments primarily for marketing activities and support services from a variety of vendors to be used in the ordinary course of business totaling $132 million at December 31, 2015. Of this amount, we expect to purchase $73 million in 2016, $53 million in 2017 through 2018, $6 million in 2019 through 2020 and none in 2021 and thereafter. These amounts do not represent our entire anticipated purchases in the future, but represent only those items for which we were contractually committed as of December 31, 2015.

Other Financial Information

12 Months Ended

Dec. 31, 2015

Additional Financial Information Disclosure [Abstract]

Other Financial Information

Other Current Assets

The following table presents details of other current assets in our consolidated balance sheets:



	As of December 31,
	2015		2014
	(Dollars in millions)
Prepaid expenses	$	46	45
Other	77		80
Total other current assets	$	123	125

Selected Current Liabilities

Current liabilities reflected in our consolidated balance sheets include accounts payable:

Included in accounts payable at December 31, 2015 and 2014, were $29 million and $44 million, respectively, associated with capital expenditures.

Labor Union Contracts	12 Months Ended
Labor Union Contracts	Dec. 31, 2015
Labor Union Contracts
Labor Union Contracts	Labor Union Contracts Approximately 11,000, or 50%, of our employees are members of various bargaining units represented by the Communications Workers of America ("CWA") or the International Brotherhood of Electrical Workers ("IBEW") and are subject to collective bargaining agreements that expire in 2017.

Basis of Presentation and Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Consolidation Policy

The accompanying consolidated financial statements include our accounts and the accounts of our subsidiaries. Intercompany amounts and transactions with our consolidated subsidiaries have been eliminated. Transactions with our non-consolidated affiliates (referred to herein as affiliates) have not been eliminated.

Use of Estimates

Our consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles. These accounting principles require us to make certain estimates, judgments and assumptions. We believe that the estimates, judgments and assumptions we make when accounting for specific items and matters, including, but not limited to, long-term contracts, customer retention patterns, allowance for doubtful accounts, depreciation, amortization, asset valuations, rates used for affiliate cost allocations, internal labor capitalization rates, recoverability of assets (including deferred tax assets), impairment assessments, pension, post-retirement and other post-employment benefits, taxes, certain liabilities and other provisions and contingencies, are reasonable, based on information available at the time they are made. Our accounting for CenturyLink's indirect acquisition of us required extensive use of estimates in determining the acquisition date fair values of our assets and liabilities. These estimates, judgments and assumptions can materially affect the reported amounts of assets, liabilities and components of stockholder's equity or deficit as of the dates of the consolidated balance sheets, as well as the reported amounts of revenues, expenses and components of cash flows during the periods presented in our other consolidated financial statements. We also make estimates in our assessments of potential losses in relation to threatened or pending tax and legal matters. See Note 11—Income Taxes and Note 15—Commitments and Contingencies for additional information.

For matters not related to income taxes, if a loss is considered probable and the amount can be reasonably estimated, we recognize an expense for the estimated loss. If we have the potential to recover a portion of the estimated loss from a third party, we make a separate assessment of recoverability and reduce the estimated loss if recovery is also deemed probable.

For matters related to income taxes, if we determine that the impact of an uncertain tax position is more likely than not to be sustained upon audit by the relevant taxing authority, then we recognize a benefit for the largest amount that is more likely than not to be sustained. No portion of an uncertain tax position will be recognized if the position has less than a 50% likelihood of being sustained. Interest is recognized on the amount of unrecognized benefit from uncertain tax positions.

For all of these and other matters, actual results could differ materially from our estimates.

Revenue Recognition

We recognize revenue for services when the related services are provided. Recognition of certain payments received in advance of services being provided is deferred until the service is provided. These advance payments include activation and installation charges, which we recognize as revenue over the expected customer relationship period, which ranges from eighteen months to over ten years depending on the service. We also defer costs for customer activations and installations. The deferral of customer activation and installation costs is limited to the amount of revenue deferred on advance payments. Costs in excess of advance payments are recorded as expense in the period such costs are incurred. Expected customer relationship periods are estimated using historical experience. In most cases, termination fees or other fees on existing contracts that are negotiated in conjunction with new contracts are deferred and recognized over the new contract term.

We offer bundle discounts to our customers who receive certain groupings of services. These bundle discounts are recognized concurrently with the associated revenue and are allocated to the various services in the bundled offering based on the estimated selling price of services included in each bundled combination.

Customer arrangements that include both equipment and services are evaluated to determine whether the elements are separable. If the elements are deemed separable and separate earnings processes exist, the revenue associated with the customer arrangement is allocated to each element based on the relative estimated selling price of the separate elements. We have estimated the selling prices of each element by reference to vendor-specific objective evidence of selling prices when the elements are sold separately. The revenue associated with each element is then recognized as earned. For example, if we receive an advance payment when we sell equipment and continuing service together, we immediately recognize as revenue the amount allocated to the equipment as long as all the conditions for revenue recognition have been satisfied. The portion of the advance payment allocated to the service based upon its relative selling price is recognized ratably over the longer of the contractual period or the expected customer relationship period.

We periodically transfer optical capacity assets on our network to other telecommunications service carriers. These transactions are structured as indefeasible rights of use, commonly referred to as IRUs, which are the exclusive right to use a specified amount of capacity or fiber for a specified term, typically 20 years. We account for the cash consideration received on transfers of optical capacity assets and on all of the other elements deliverable under an IRU, as revenue ratably over the term of the agreement. We have not recognized revenue on any contemporaneous exchanges of our optical capacity assets for other optical capacity assets.

In connection with offering products and services provided by third-party vendors, we review the relationship between us, the vendor and the end customer to assess whether revenue should be reported on a gross or net basis. In assessing whether revenue should be reported on a gross or net basis, we consider whether we act as a principal in the transaction, take title to the products, have risk and rewards of ownership or act as an agent or broker. Based on CenturyLink's agreements with DIRECTV and Verizon Wireless, we offer these services through sales agency relationships which are reported on a net basis.

Affiliate Transactions

We provide to our affiliates telecommunications services that we also provide to external customers. In addition, we provide to our affiliates computer system development and support services. Services provided by us to our affiliates are recognized as operating revenue-affiliates in our consolidated statements of operations. We also purchase services from our affiliates including telecommunications services, marketing and employee-related support services. Services provided to us from our affiliates are recognized as operating expenses-affiliates on our consolidated statements of operations. Because of the significance of the services we provide to our affiliates and our affiliates provide to us, the results of operations, financial position and cash flows presented herein are not necessarily indicative of the results of operations, financial position and cash flows we would have achieved had we operated as a stand-alone entity during the periods presented.

We recognize intercompany charges at the amounts billed to us by our affiliates and we recognize intercompany revenue for services we bill to our affiliates. Regulatory rules require certain revenues and expenses to be recorded at market price or fully distributed cost. Our compliance with regulations is subject to review by regulators. Adjustments to intercompany charges that result from these reviews are recorded in the period they become known.

CenturyLink has cash management arrangements between certain of its subsidiaries that include lines of credit, affiliate obligations, capital contributions and dividends. As part of these cash management arrangements, an affiliate provides lines of credit to certain other affiliates. Amounts outstanding under these lines of credit and intercompany obligations vary from time to time. Under these arrangements, the majority of our cash balance is transferred on a daily basis to CenturyLink and most affiliate transactions are deemed to be settled at the time the transactions are recorded in our accounting records, with the resulting net balance at the end of each period reflected as advances to affiliates on the accompanying consolidated balance sheets. From time to time we declare and pay dividends to our parent, QSC, which are settled through the advances to affiliates, which has the net effect of reducing the amount of these advances. Dividends declared are reflected on our consolidated statements of stockholder's equity and the consolidated statements of cash flows reflects the changes in advances to affiliates as investing activities and changes in advances from affiliates as financing activities. Interest is assessed on the advances to/from affiliates on either the three-month U.S T-bill rate (for advances to affiliates) or CenturyLink’s weighted average borrowing rate (for advances from affiliates).

The affiliates obligations, net in current and noncurrent liabilities on our consolidated balance sheets primarily represents the cumulative allocation of expense, net of payments, associated with QCII’s pension plans and post-retirement benefits plans prior to the plan mergers. In 2015, we agreed to a plan to settle the outstanding affiliate obligations, net balance with QCII over a 30 year term. Payments will be made on a monthly basis. For the year ended December 31, 2015, we made a settlement payment of $105 million to QCII on our affiliate obligations, net balance. Changes in the affiliates obligations, net are reflected in operating activities on our consolidated statements of cash flows.

In the normal course of business, we transfer assets to and from various affiliates through our parent, QSC, which are recorded through our equity. It is our policy to record asset transfers based on carrying values.

USF, Gross Receipts Taxes and Other Surcharges

In determining whether to include in our revenues and expenses the taxes and surcharges collected from customers and remitted to government authorities, including USF charges, sales, use, value added and some excise taxes, we assess, among other things, whether we are the primary obligor or principal taxpayer for the taxes assessed in each jurisdiction where we do business. In jurisdictions where we determine that we are the principal taxpayer, we record the surcharges on a gross basis and include them in our revenues and costs of services and products.

In jurisdictions where we determine that we are merely a collection agent for the government authority, we record the taxes on a net basis and do not include them in our revenues and costs of services and products.

Advertising Costs

Costs related to advertising are expensed as incurred and included in selling, general and administrative expenses in our consolidated statements of operations. Our advertising expense was $84 million, $83 million and $88 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Legal Costs

In the normal course of our business, we incur costs to hire and retain external legal counsel to advise us on regulatory, litigation and other matters. We expense these costs as the related services are received.

Income Taxes

Our results are included in the CenturyLink consolidated federal income tax return and certain combined state income tax returns. CenturyLink allocates income tax expense to us based upon a separate return allocation method which results in income tax expense that approximates the expense that would result if we were a stand-alone entity. Our reported deferred tax assets and liabilities, as discussed below and in Note 11—Income Taxes, are primarily determined as a result of the application of the separate return allocation method and therefore the settlement of these amounts is dependent upon our parent, CenturyLink, rather than tax authorities. Our current expectation is that the vast majority of deferred tax assets and liabilities will be settled through our general intercompany obligation based upon the current CenturyLink policy. CenturyLink has the right to change their policy regarding settlement of these assets and liabilities at any time.

The provision for income taxes consists of an amount for taxes currently payable, an amount for tax consequences deferred to future periods and adjustments to our liabilities for uncertain tax positions. We record deferred income tax assets and liabilities reflecting future tax consequences attributable to differences between the financial statement carrying value of assets and liabilities and the tax bases of those assets and liabilities. Deferred taxes are computed using enacted tax rates expected to apply in the year in which the differences are expected to affect taxable income. The effect on deferred income tax assets and liabilities of a change in tax rate is recognized in earnings in the period that includes the enactment date.

We establish valuation allowances when necessary to reduce deferred income tax assets to the amounts that we believe are more likely than not to be recovered. Each quarter we evaluate the need to retain all or a portion of the valuation allowance on our deferred tax assets. See Note 11—Income Taxes for additional information.

Cash and Cash Equivalents

Cash and cash equivalents include highly liquid investments that are readily convertible into cash and are not subject to significant risk from fluctuations in interest rates. As a result, the value at which cash and cash equivalents are reported in our consolidated financial statements approximates their fair value. Our cash collections are transferred to CenturyLink on a daily basis and our ultimate parent funds our cash disbursement needs. The net cash transferred to CenturyLink has been reflected as advances to affiliates in our consolidated balance sheets.

Accounts Receivable and Allowance for Doubtful Accounts

Accounts receivable are recognized based upon the amount due from customers for the services provided or at cost for purchased and other receivables less an allowance for doubtful accounts. The allowance for doubtful accounts receivable reflects our best estimate of probable losses inherent in our receivable portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other currently available evidence. We generally consider our accounts past due if they are outstanding over 30 days. Our collection process varies by the customer segment, amount of the receivable, and our evaluation of the customer's credit risk. Our past due accounts are written off against our allowance for doubtful accounts when collection is considered to be not probable. Any recoveries of accounts previously written off are generally recognized as a reduction in bad debt expense in the period received. The carrying value of accounts receivable net of the allowance for doubtful accounts approximates fair value.

Property, Plant and Equipment

As a result of our indirect acquisition by CenturyLink, property, plant and equipment acquired at the time of acquisition was recorded based on its estimated fair value as of the acquisition date. Subsequently purchased and constructed property, plant and equipment is recorded at cost. Property, plant and equipment is depreciated primarily using the straight-line group method. Under the straight-line group method, assets dedicated to providing telecommunications services (which comprise the majority of our property, plant and equipment) that have similar physical characteristics, use and expected useful lives are pooled for purposes of depreciation and tracking. The equal life group procedure is used to establish each pool's average remaining useful life. Generally, under the straight-line group method, when an asset is sold or retired in the course of normal business activities, the cost is deducted from property, plant and equipment and charged to accumulated depreciation without recognition of a gain or loss. A gain or loss is recognized in our consolidated statements of operations only if a disposal is abnormal or unusual. Leasehold improvements are amortized over the shorter of the useful lives of the assets or the expected lease term. Expenditures for maintenance and repairs are expensed as incurred. Interest is capitalized during the construction phase of network and other internal-use capital projects. Employee-related costs for construction of network and other internal use assets are also capitalized during the construction phase. Property, plant and equipment supplies used internally are carried at average cost, except for significant individual items for which cost is based on specific identification.

We perform annual internal reviews to evaluate the reasonableness of the depreciable lives for our property, plant and equipment. Our reviews utilize models that take into account actual usage, physical wear and tear, replacement history, assumptions about technology evolution and, in certain instances, actuarially determined probabilities to estimate the remaining useful life of our asset base. Our remaining useful life assessments anticipate the loss in service value of assets that may precede the physical retirement. Assets shared among many customers may lose service value as those customers leave the network. However, the asset is not retired until all customers no longer utilize the asset and we determine there is no alternative use for the asset.

We review long-lived tangible assets for impairment whenever facts and circumstances indicate that the carrying amounts of the assets may not be recoverable. For assessment purposes, long-lived assets are grouped with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities, absent a material change in operations. An impairment loss is recognized only if the carrying amount of the asset group is not recoverable and exceeds its fair value. Recoverability of the asset group to be held and used is assessed by comparing the carrying amount of the asset group to the estimated undiscounted future net cash flows expected to be generated by the asset group. If the asset group's carrying value is not recoverable, an impairment charge is recognized for the amount by which the carrying amount of the asset group exceeds its fair value. We determine fair values by using a combination of comparable market values and discounted cash flows, as appropriate.

Goodwill, Customer Relationships and Other Intangible Assets

Intangible assets arising from business combinations, such as goodwill, customer relationships and capitalized software are initially recorded at estimated fair value. We amortize customer relationships primarily over an estimated life of ten years, using either the sum-of-the-years-digits or the straight-line methods, depending on the type of customer. We amortize capitalized software using the straight-line method over estimated lives ranging up to seven years. Other intangible assets not arising from business combinations are initially recorded at cost.

Internally used software, whether purchased or developed by us, is capitalized and amortized using the straight-line method over its estimated useful life. We have capitalized certain costs associated with software such as costs of employees devoting time to the projects and external direct costs for materials and services. Costs associated with software to be used for internal purposes are expensed until the point at which the project has reached the development stage. Subsequent additions, modifications or upgrades to internal-use software are capitalized only to the extent that they allow the software to perform a task it previously did not perform. Software maintenance, data conversion and training costs are expensed in the period in which they are incurred. We review the remaining economic lives of our capitalized software annually. Capitalized software is included in other intangible assets, net, in our consolidated balance sheets.

We are required to assess goodwill for impairment at least annually, or more frequently, if an event occurs or circumstances change that would indicate an impairment may have occurred. We are required to write-down the value of goodwill in periods in which the recorded amount of goodwill exceeds the implied fair value of goodwill. The impairment assessment is performed annually at the reporting unit level. We have determined that our operations consist of one reporting unit, consistent with our determination that our business consists of one operating segment. See Note 2—Goodwill, Customer Relationships and Other Intangible Assets for additional information.

Pension and Post-Retirement Benefits

A substantial portion of our active and retired employees participate in the CenturyLink Combined Pension Plan. On December 31, 2014, the QCII pension plan and a pension plan of an affiliate were merged into the CenturyLink Retirement Plan. The CenturyLink Retirement Plan was renamed the CenturyLink Combined Pension Plan. Prior to the pension plan merger, the above-noted employees participated in the QCII pension plan. In addition, certain employees may become eligible to participate in CenturyLink's post-retirement health care and life insurance benefit plans. CenturyLink allocates service costs relating to pension and post-retirement health care and life insurance benefits to us and its other affiliates. The amounts contributed by us through CenturyLink are not segregated or restricted to pay amounts due to our employees and may be used to provide benefits to other employees of CenturyLink. The allocation of the service costs to us is based upon our employees who are currently earning benefits under the plans.

For further information on qualified pension, post-retirement and other post-employment benefit plans, see CenturyLink's Annual Report on Form 10-K for the year ended December 31, 2015.

Recent Accounting Pronouncements

Recently Adopted Accounting Pronouncements

In 2015, we adopted Accounting Standards Update (“ASU”) 2015-03 “Simplifying the Presentation of Debt Issuance Costs” (ASU 2015-03) and ASU 2015-17 “Balance Sheet Classification of Deferred Taxes” (ASU 2015-17). Both ASUs are intended to simplify the presentation of financial information. ASU 2015-03 requires that debt issuance costs be presented as a reduction in the associated debt rather than as an other asset, net. ASU 2015-17 requires that deferred taxes be presented on a net basis by jurisdiction as either a net noncurrent asset or liability. The ASUs affect neither the timing of expense recognition related to the debt issuance costs nor the timing of income and expense recognition related to deferred income taxes.

We adopted both ASU 2015-03 and 2015-17 by retrospectively applying the requirements of the ASUs to our previously issued consolidated financial statements. The retrospective application had no impact on our net income for the years ended December 31, 2014 and 2013, but resulted in the following changes in our previously reported consolidated balance sheet as of December 31, 2014:


•	A decrease of $163 million in Total current assets;


•	A decrease of $109 million in Other assets, net;


•	A decrease of $110 million in Long-term debt; and


•	A decrease of $162 million in Deferred income taxes, net.

The adoption of the ASUs had no impact on our net cash provided by operating activities but did change the presentation of the adjustments to reconcile net income and changes in other noncurrent assets and liabilities, net for the years ended December 31, 2014 and 2013.

Recent Accounting Pronouncements

Leases

On February 25, 2016, the FASB issued ASU 2016-02, “Leases” (“ASU 2016-02”). The core principle of ASU 2016-02 will require lessees to present right-of-use assets and lease liabilities on their balance sheets.

ASU 2016-02 is effective for annual and interim periods beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. Upon adoption of ASU 2016-02, we are required to recognize and measure leases at the beginning of the earliest period presented in our consolidated financial statements using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that we may elect to apply. We have not yet decided when we will adopt ASU 2016-02 or which practical expedient options we will elect. We are currently evaluating and assessing the impact ASU 2016-02 will have on us and our consolidated financial statements. As of the date of this Annual Report, we cannot provide any estimate of the impact of adopting ASU 2016-02.

Revenue Recognition

On May 28, 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09” or “new standard”). The new standard replaces virtually all existing generally accepted accounting principles (“GAAP”) on revenue recognition and replaces them with a principles-based approach for determining revenue recognition using a new five step model. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 also includes new accounting principles related to the deferral and amortization of contract acquisition and fulfillment costs. We currently do not defer any contract acquisition costs and defer contract fulfillment costs only up to the extent of any revenue deferred.

On July 9, 2015, the FASB approved the deferral of the effective date of ASU 2014-09 by one year until January 1, 2018. Early adoption is permitted as of January 1, 2017. ASU 2014-09 may be adopted by applying the provisions of the new standard on a retrospective basis to the periods included in the financial statements or on a modified retrospective basis which would result in the recognition of a cumulative effect of adopting ASU 2014-09 in the first quarter of 2017, if adopting early, otherwise in the first quarter of 2018. We have not yet decided which implementation method we will adopt. We are studying the new standard and are in the early stages of assessing the impact the new standard will have on us and our consolidated financial statements. We cannot at this time, however, provide any estimate of the impact of adopting the new standard.

Goodwill, Customer Relationships and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of goodwill, customer relationships and other intangible assets

Goodwill, customer relationships and other intangible assets consisted of the following:



	As of December 31,
	2015		2014
	(Dollars in millions)
Goodwill	$	9,354	9,354
Customer relationships, less accumulated amortization of $3,264 and $2,660	2,435		3,039
Other intangible assets subject to amortization:
Capitalized software, less accumulated amortization of $1,383 and $1,247	613		808

Summary of amortization expense

Total amortization expense for intangible assets was as follows:



	Years Ended December 31,
	2015		2014	2013
	(Dollars in millions)
Amortization expense for intangible assets	$	871	957	1,029

Schedule of estimated amortization expense for intangible assets

We estimate that total amortization expense for intangible assets for the years ending December 31, 2016 through 2020 will be as follows:



	(Dollars in millions)
Year ending December 31,
2016	$	725
2017	661
2018	587
2019	507
2020	435

Long-Term Debt and Revolving Promissory Note (Tables)

12 Months Ended

Dec. 31, 2015

Debt Disclosure [Abstract]

Schedule of long-term debt, including unamortized discounts and premiums

Long-term debt, including unamortized premiums and discounts, unamortized debt issuance costs and note payable-affiliate, were as follows:



			As of December 31,
	Interest Rates	Maturities	2015			2014
			(Dollars in millions)
Senior notes	6.125% - 8.375%	2016 - 2055	$	7,229		7,311
Term loan	2.180%	2025	100			—
Capital lease and other obligations	Various	Various	17			32
Unamortized premiums, net			16			36
Unamortized debt issuance costs			(123		)	(110	)
Total long-term debt			7,239			7,269
Less current maturities			(242		)	(117	)
Long-term debt, excluding current maturities			$	6,997		7,152
Note payable-affiliate	6.758%	2022	$	855		796

Schedule of aggregate maturities of the entity's long-term debt (excluding unamortized premiums, discounts, and other)

Set forth below is the aggregate principal amount of our long-term debt (excluding unamortized premiums and discounts, net and unamortized debt issuance costs and other and excluding note payable-affiliate) maturing during the following years:



	(Dollars in millions)⁽¹⁾
2016	$	242
2017	503
2018	3
2019	1
2020	—
2021 and thereafter	6,597
Total long-term debt	$	7,346

_______________________________________________________________________________

⁽¹⁾Actual principal paid in all years may differ due to the possible future refinancing of outstanding debt or the issuance of new debt.

Schedule of amount of gross interest expense, net of capitalized interest and interest expense (income)-affiliates

Interest expense includes interest on long-term debt. The following table presents the amount of gross interest expense, net of capitalized interest and interest expense-affiliates, net:



	Years Ended December 31,
	2015			2014		2013
	(Dollars in millions)
Interest expense:
Gross interest expense	$	491		481		467
Capitalized interest	(18		)	(17	)	(17	)
Total interest expense	$	473		464		450
Interest expense-affiliates, net	$	53		40		64

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 505
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-Section 50
-Paragraph 3
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section 50
-Paragraph 8
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 505
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

+ Details

Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2015

Receivables [Abstract]

Schedule of the entity's accounts receivable balances

The following table presents details of our accounts receivable balances:



	As of December 31,
	2015			2014
	(Dollars in millions)
Trade and purchased receivables	$	620		649
Earned and unbilled receivables	111			120
Other	4			9
Total accounts receivable	735			778
Less: allowance for doubtful accounts	(47		)	(38	)
Accounts receivable, less allowance	$	688		740

Schedule of the entity's allowance for doubtful accounts

The following table presents details of our allowance for doubtful accounts:



	Beginning Balance		Additions	Deductions		Ending Balance
	(Dollars in millions)
2015	$	38	78	(69	)	47
2014	$	43	64	(69	)	38
2013	$	46	65	(68	)	43

Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Schedule of net property, plant and equipment

Net property, plant and equipment is composed of the following:



	Depreciable Lives	As of December 31,
	Depreciable Lives	2015			2014
		(Dollars in millions)
Property, plant and equipment:
Land	N/A	$	349		350
Fiber, conduit and other outside plant⁽¹⁾	15-45 years	5,362			4,640
Central office and other network electronics⁽²⁾	4-10 years	3,614			3,362
Support assets⁽³⁾	5-30 years	2,584			2,496
Construction in progress⁽⁴⁾	N/A	273			309
Gross property, plant and equipment		12,182			11,157
Accumulated depreciation		(4,808		)	(3,956	)
Net property, plant and equipment		$	7,374		7,201

_______________________________________________________________________________


⁽¹⁾	Fiber, conduit and other outside plant consists of fiber and metallic cable, conduit, poles and other supporting structures.


⁽²⁾	Central office and other network electronics consists of circuit and packet switches, routers, transmission electronics and electronics providing service to customers.


⁽³⁾	Support assets consist of buildings, computers and other administrative and support equipment.


⁽⁴⁾	Construction in progress includes inventory held for construction and property of the aforementioned categories that has not been placed in service as it is still under construction.

Severance (Tables)

12 Months Ended

Dec. 31, 2015

Restructuring and Related Activities [Abstract]

Schedule of changes in accrued liability for severance expenses

Changes in our accrued liability for severance expenses were as follows:



	Severance
	(Dollars in millions)
Balance at December 31, 2013	$	5
Accrued to expense	44
Payments, net	(39		)
Balance at December 31, 2014	$	10
Accrued to expense	51
Payments, net	(55		)
Balance at December 31, 2015	$	6

Products and Services Revenues (Tables)

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Schedule of operating revenues by products and services

Our operating revenues for our products and services consisted of the following categories for the years ended December 31, 2015, 2014 and 2013:



	Years Ended December 31,
	2015		2014	2013
	(Dollars in millions)
Strategic services	$	3,433	3,429	3,342
Legacy services	2,777		2,987	3,208
Affiliates and other services	2,754		2,422	2,203
Total operating revenues	$	8,964	8,838	8,753

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Summary of open income tax years by jurisdiction

Our open income tax years by major jurisdiction are as follows at December 31, 2015:



Jurisdiction		Open Tax Years
Federal		2012—current
State
Arizona		2010—current
Florida		2010—current
Other states		2011—current

Schedule of components of the income tax expense from continuing operations

The components of the income tax expense from continuing operations are as follows:



	Years Ended December 31,
	2015			2014		2013
	(Dollars in millions)
Income tax expense:
Current tax provision:
Federal and foreign	$	734		738		653
State and local	114			129		101
Total current tax provision	848			867		754
Deferred tax expense:
Federal and foreign	(170		)	(209	)	(125	)
State and local	(19		)	(19	)	(27	)
Total deferred tax expense	(189		)	(228	)	(152	)
Income tax expense	$	659		639		602

Schedule of effective income tax rate for continuing operations that differs from the statutory tax rate

The effective income tax rate for continuing operations differs from the statutory tax rate as follows:



	Years Ended December 31,
	2015		2014		2013
	(in percent)
Effective income tax rate:
Federal statutory income tax rate	35.0	%	35.0	%	35.0	%
State income taxes-net of federal effect	3.6	%	4.0	%	3.1	%
Other	(0.6	)%	0.7	%	0.3	%
Effective income tax rate	38.0	%	39.7	%	38.4	%

Schedule of components of the deferred tax assets and liabilities

The components of the deferred tax assets and liabilities are as follows:



	As of December 31,
	2015			2014
	(Dollars in millions)
Deferred tax assets and liabilities:
Deferred tax liabilities:
Property, plant and equipment	$	(1,431	)	(1,380	)
Intangibles assets	(1,153		)	(1,449	)
Receivable from an affiliate due to pension plan participation	(460		)	(500	)
Other	(59		)	(52	)
Total deferred tax liabilities	(3,103		)	(3,381	)
Deferred tax assets:
Payable to affiliate due to post-retirement benefit plan participation	921			998
Debt premiums	21			36
Other	277			274
Total deferred tax assets	1,219			1,308
Valuation allowance on deferred tax assets	(12		)	(12	)
Net deferred tax assets	1,207			1,296
Net deferred tax liabilities	$	(1,896	)	(2,085	)

Fair Value Disclosure (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Schedule of the three input levels in the hierarchy of fair value measurements

The three input levels in the hierarchy of fair value measurements are defined by the FASB generally as follows:



Input Level		Description of Input
Level 1		Observable inputs such as quoted market prices in active markets.
Level 2		Inputs other than quoted prices in active markets that are either directly or indirectly observable.
Level 3		Unobservable inputs in which little or no market data exists.

Schedule of carrying amounts and estimated fair values of long-term debt, excluding capital lease obligations, and input levels to determine fair values

The following table presents the carrying amounts and estimated fair values of our long-term debt, excluding capital lease and other obligations and unamortized debt issuance costs, as well as the input levels used to determine the fair values:



		As of December 31, 2015			As of December 31, 2014
	Input Level	Carrying Amount		Fair Value	Carrying Amount	Fair Value
		(Dollars in millions)
Liabilities-Long-term debt (excluding capital lease and other obligations)	2	$	7,222	7,456	7,237	7,702

Stockholder's Equity (Tables)

12 Months Ended

Dec. 31, 2015

Stockholders' Equity Note [Abstract]

Schedule of cash dividends declared

We declared the following cash dividend to QSC:



	Years Ended December 31,
	2015		2014	2013
	(Dollars in millions)
Cash dividend declared to QSC	$	1,350	1,400	1,325
Cash dividend paid to QSC	1,350		1,400	1,325

Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Schedule of quarterly financial information



	First Quarter		Second Quarter	Third Quarter	Fourth Quarter	Total
	(Dollars in millions)
2015
Operating revenues	$	2,217	2,222	2,287	2,238	8,964
Operating income	545		521	572	622	2,260
Income tax expense	167		152	171	169	659
Net income	247		238	268	321	1,074



	First Quarter		Second Quarter	Third Quarter	Fourth Quarter	Total
	(Dollars in millions)
2014
Operating revenues	$	2,211	2,206	2,198	2,223	8,838
Operating income	542		546	528	496	2,112
Income tax expense	160		162	156	161	639
Net income	253		256	245	216	970

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Summary of the entity's capital lease activity

The tables below summarize our capital lease activity:



	Years Ended December 31,
	2015		2014	2013
	(Dollars in millions)
Assets acquired through capital leases	$	10	3	—
Depreciation expense	19		32	42
Cash payments towards capital leases	20		32	40



	As of December 31,
	2015		2014
	(Dollars in millions)
Assets included in property, plant and equipment	$	66	137
Accumulated depreciation	55		108

Schedule of future annual minimum payments under capital lease

The future annual minimum payments under capital lease arrangements as of December 31, 2015 were as follows:



	Future Minimum Payments
	(Dollars in millions)
Capital lease obligations:
2016	$	8
2017	4
2018	4
2019	2
2020	—
2021 and thereafter	5
Total minimum payments	23
Less: amount representing interest and executory costs	(7		)
Present value of minimum payments	16
Less: current portion	(6		)
Long-term portion	$	10

Schedule of future minimum payments under operating leases

At December 31, 2015, our future rental commitments for operating leases were as follows:



	Future Minimum Payments
	(Dollars in millions)
Operating leases:
2016	$	56
2017	50
2018	45
2019	37
2020	32
2021 and thereafter	52
Total future minimum payments⁽¹⁾	$	272

_______________________________________________________________________________


⁽¹⁾	Minimum payments have not been reduced by minimum sublease rentals of $30 million due in the future under non-cancelable subleases.

Other Financial Information (Tables)

12 Months Ended

Dec. 31, 2015

Additional Financial Information Disclosure [Abstract]

Schedule of other current assets

The following table presents details of other current assets in our consolidated balance sheets:



	As of December 31,
	2015		2014
	(Dollars in millions)
Prepaid expenses	$	46	45
Other	77		80
Total other current assets	$	123	125

Schedule of accounts payable and accrued liabilities

Current liabilities reflected in our consolidated balance sheets include accounts payable:

Basis of Presentation and Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in accounting estimates
Depreciation expense									$ 986	$ 1,048	$ 1,099
Net income	$ 321	$ 268	$ 238	$ 247	$ 216	$ 245	$ 256	$ 253	1,074	$ 970	$ 964
Switch, circuit and cable network equipment \| Service life
Change in accounting estimates
Depreciation expense									20
Net income									(12)
Pension, Supplemental and Other Postretirement Benefit Plans \| Change in accounting method accounted for as change in estimate
Change in accounting estimates
Decrease in defined benefit plans net periodic benefit cost									$ (7)
Decrease in defined benefit plans net periodic benefit cost (financial effect)									The change in methodology resulted in a decrease of $7 million to our net periodic benefit cost for the year ended December 31, 2015

Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Summary of Significant Accounting Policies (Details 2) $ in Millions		3 Months Ended		12 Months Ended
	Aug. 27, 2015 USD ($)	Dec. 31, 2015 USD ($) state	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) state
Products and Services Revenues
Number of states in which entity operates \| state		14		14
Incremental increase in other operating revenues - CAF Phase II		$ 31	$ 64
CAF Phase 2 Support \| CenturyLink, Inc.
Products and Services Revenues
Federal support, total amount per agreement	$ 500
Contract or agreement term (in years)	6
Number of rural households and businesses	1,200,000
Number of states in which entity operates	33
CAF Phase 2 Support \| Qwest Corporation
Products and Services Revenues
Federal support, total amount per agreement	$ 150
Number of rural households and businesses	300,000
Number of states in which entity operates	13
Incremental increase in other operating revenues - CAF Phase II				$ 95

Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Summary of Significant Accounting Policies (Details 3) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) state	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Revenue Recognition
Term of indefeasible rights of use (in years)	20 years
Advertising Costs
Advertising expense	$ 84	$ 83	$ 88
Accounts Receivable and Allowance for Doubtful Accounts
Period accounts receivable are past due	30 days
Number of states in which entity operates \| state	14
Activation and installation charges \| Minimum
Revenue Recognition
Customer relationship period for revenue recognition (from eighteen months to over ten years)	18 months
Activation and installation charges \| Maximum
Revenue Recognition
Customer relationship period for revenue recognition (from eighteen months to over ten years)	10 years
Qwest Communications International, Inc.
Affiliate Transactions
Description of related party transaction	In 2015, we agreed to a plan to settle the outstanding affiliate obligations, net balance with QCII over a 30 year term. Payments will be made on a monthly basis.
Repayments on affiliate obligation	$ 105

Basis of Presentation and Summary of Significant Accounting Policies (Details 4)	12 Months Ended
	Dec. 31, 2015 segment
Goodwill, Customer Relationships and Other Intangible Assets
Number of reporting units	1
Number of operating segments	1
Customer relationships
Goodwill, Customer Relationships and Other Intangible Assets
Finite-lived intangible assets, maximum useful life	10 years
Capitalized software
Goodwill, Customer Relationships and Other Intangible Assets
Finite-lived intangible assets, maximum useful life	7 years

Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Summary of Significant Accounting Policies (Details 5) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
New Accounting Pronouncement, Early Adoption [Line Items]
Net income	$ 321,000,000	$ 268,000,000	$ 238,000,000	$ 247,000,000	$ 216,000,000	$ 245,000,000	$ 256,000,000	$ 253,000,000	$ 1,074,000,000	$ 970,000,000	$ 964,000,000
Total current assets	1,602,000,000				1,683,000,000				1,602,000,000	1,683,000,000
Other assets, net	92,000,000				100,000,000				92,000,000	100,000,000
Long-term debt, excluding current maturities	6,997,000,000				7,152,000,000				6,997,000,000	7,152,000,000
Deferred income taxes, net	$ 1,896,000,000				2,085,000,000				$ 1,896,000,000	2,085,000,000
Restatement adjustment \| New accounting pronouncement, early adoption, effect
New Accounting Pronouncement, Early Adoption [Line Items]
Net income										0	0
Total current assets					(163,000,000)					(163,000,000)
Other assets, net					(109,000,000)					(109,000,000)
Long-term debt, excluding current maturities					(110,000,000)					(110,000,000)
Deferred income taxes, net					$ (162,000,000)					(162,000,000)
Net cash provided by (used in) operating activities										$ 0	$ 0

Goodwill, Customer Relationships and Other Intangible Assets (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) segment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 9,354	$ 9,354
Gross carrying amounts of goodwill, customer relationships and other intangible assets	17,049
Amortization expense for intangible assets	$ 871	957	$ 1,029
Number of reporting units \| segment	1
Weighted average cost of capital to calculate discount rate as of the measurement date (as a percent)	6.00%
Weighted average cost of capital, cost of equity (as a percent)	7.60%
Weighted average cost of capital, after-tax cost of debt (as a percent)	3.30%
Estimated amortization expense for intangible assets
2016	$ 725
2017	661
2018	587
2019	507
2020	435
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	2,435	3,039
Accumulated amortization	3,264	2,660
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	613	808
Accumulated amortization	$ 1,383	$ 1,247

Long-Term Debt and Revolving Promissory Note (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Long-term debt
Long-term debt, gross	$ 7,346
Capital lease and other obligations	17	$ 32
Unamortized premiums, net	16	36
Unamortized debt issuance costs	(123)	(110)
Total long-term debt	7,239	7,269
Less current maturities	(242)	(117)
Long-term debt, excluding current maturities	6,997	7,152
Revolving promissory note
Note payable - affiliate	855	796
Senior notes
Long-term debt
Long-term debt, gross	$ 7,229	7,311
Senior notes \| Minimum
Long-term debt
Interest rate, stated percentage (as a percent)	6.125%
Senior notes \| Maximum
Long-term debt
Interest rate, stated percentage (as a percent)	8.375%
Term loan
Long-term debt
Long-term debt, gross	$ 100	0
Term loan interest rate at period end (as a percent)	2.18%
Revolving promissory note \| Revolving promissory note \| CenturyLink, Inc. affiliate \| Qwest Corporation
Revolving promissory note
Short-term debt, weighted average interest rate (as a percent)	6.758%
Note payable - affiliate	$ 855	$ 796
Maximum borrowing capacity, note payable-affiliate	1,000
Accrued interest payable. note payable-affiliate	$ 5

Long-Term Debt and Revolving Promissory Note Long-Term Debt and Revolving Promissory Note (Details 2) - USD ($) $ in Millions					12 Months Ended
	Jan. 31, 2016	Sep. 21, 2015	Feb. 20, 2015	Sep. 29, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 13, 2015	Sep. 30, 2015	Jun. 15, 2015	Oct. 01, 2014
Debt Instrument [Line Items]
Long-term debt, gross					$ 7,346
Amount of gross interest expense, net of capitalized interest and interest expense - affiliates
Gross interest expense					491	$ 481	$ 467
Capitalized interest					(18)	(17)	(17)
Total interest expense					473	464	450
Interest expense-affiliates, net					53	40	$ 64
Senior notes
Debt Instrument [Line Items]
Long-term debt, gross					7,229	7,311
Term loan
Debt Instrument [Line Items]
Long-term debt, gross					$ 100	$ 0
Qwest Corporation \| Senior notes \| 6.625% Notes due 2055
Debt Instrument [Line Items]
Face amount of debt instrument		$ 400							$ 10
Interest rate, stated percentage (as a percent)		6.625%
Net proceeds from issuance of debt		$ 386
Qwest Corporation \| Senior notes \| 6.625% Notes due 2055 \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price of debt instrument (as a percent)		100.00%
Qwest Corporation \| Senior notes \| 6.875 % Notes due 2054
Debt Instrument [Line Items]
Face amount of debt instrument				$ 500
Interest rate, stated percentage (as a percent)				6.875%
Net proceeds from issuance of debt				$ 483
Qwest Corporation \| Senior notes \| 6.875 % Notes due 2054 \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price of debt instrument (as a percent)				100.00%
Qwest Corporation \| Senior notes \| 7.50%Notes due 2014
Debt Instrument [Line Items]
Interest rate, stated percentage (as a percent)											7.50%
Repurchased face amount of Senior notes											$ 600
Qwest Corporation \| Senior notes \| 7.200% Notes due 2026
Debt Instrument [Line Items]
Interest rate, stated percentage (as a percent)								7.20%
Repurchased face amount of Senior notes								$ 250
Qwest Corporation \| Senior notes \| 6.875% Noted due 2033
Debt Instrument [Line Items]
Interest rate, stated percentage (as a percent)								6.875%
Repurchased face amount of Senior notes								$ 150
Qwest Corporation \| Senior notes \| 7.625% Noted due 2015
Debt Instrument [Line Items]
Interest rate, stated percentage (as a percent)										7.625%
Repurchased face amount of Senior notes										$ 92
Qwest Corporation \| Term loan \| Term loan
Debt Instrument [Line Items]
Long-term debt, gross			$ 100
Face amount of debt instrument			$ 100
Subsequent event \| Qwest Corporation \| Senior notes \| 7.00% Notes due 2056
Debt Instrument [Line Items]
Face amount of debt instrument	$ 235
Interest rate, stated percentage (as a percent)	7.00%
Net proceeds from issuance of debt	$ 227
Subsequent event \| Qwest Corporation \| Senior notes \| 7.00% Notes due 2056 \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price of debt instrument (as a percent)	100.00%
Minimum \| Senior notes
Debt Instrument [Line Items]
Interest rate, stated percentage (as a percent)					6.125%
Minimum \| London Interbank Offered Rate (LIBOR) \| Qwest Corporation \| Term loan \| Term loan
Debt Instrument [Line Items]
Interest rate margin (as a percent)			1.50%
Minimum \| Base Rate \| Qwest Corporation \| Term loan \| Term loan
Debt Instrument [Line Items]
Interest rate margin (as a percent)			0.50%
Maximum \| Senior notes
Debt Instrument [Line Items]
Interest rate, stated percentage (as a percent)					8.375%
Maximum \| London Interbank Offered Rate (LIBOR) \| Qwest Corporation \| Term loan \| Term loan
Debt Instrument [Line Items]
Interest rate margin (as a percent)			2.50%
Maximum \| Base Rate \| Qwest Corporation \| Term loan \| Term loan
Debt Instrument [Line Items]
Interest rate margin (as a percent)			1.50%

Long-Term Debt and Revolving Promissory Note Long-Term Debt and Revolving Promissory Note (Details 3) $ in Millions	Dec. 31, 2015 USD ($)
Maturities of long-term debt (excluding unamortized premiums, net and unamortized debt issuance costs)
2016	$ 242
2017	503
2018	3
2019	1
2020	0
2021 and thereafter	6,597
Total long-term debt	$ 7,346

Accounts Receivable (Details) - USD ($)	12 Months Ended
Accounts Receivable (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Accounts receivable
Accounts receivable, gross, current				$ 735,000,000	$ 778,000,000
Other				4,000,000	9,000,000
Total accounts receivable, gross, current				735,000,000	778,000,000
Accounts receivable, allowance (in dollars)	$ (38,000,000)	$ (43,000,000)	$ (46,000,000)	(47,000,000)	(38,000,000)
Accounts receivable, less allowance				688,000,000	740,000,000
Customer receivable in excess of 10% of accounts receivable				0
Changes in allowance for doubtful accounts
Beginning balance	38,000,000	43,000,000	46,000,000
Provision for uncollectible accounts	78,000,000	64,000,000	65,000,000
Deductions	(69,000,000)	(69,000,000)	(68,000,000)
Ending balance	$ 47,000,000	$ 38,000,000	$ 43,000,000
Unbilled revenues
Accounts receivable
Accounts receivable, gross, current				111,000,000	120,000,000
Total accounts receivable, gross, current				111,000,000	120,000,000
Trade accounts receivable
Accounts receivable
Accounts receivable, gross, current				620,000,000	649,000,000
Total accounts receivable, gross, current				$ 620,000,000	$ 649,000,000

Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, plant and equipment
Property, plant and equipment	$ 12,182	$ 11,157
Accumulated depreciation	(4,808)	(3,956)
Net property, plant and equipment	7,374	7,201
Depreciation expense	986	1,048	$ 1,099
Land
Property, plant and equipment
Property, plant and equipment	349	350
Fiber, conduit and other outside plant
Property, plant and equipment
Property, plant and equipment	$ 5,362	4,640
Fiber, conduit and other outside plant \| Minimum
Property, plant and equipment
Depreciable lives	15 years
Fiber, conduit and other outside plant \| Maximum
Property, plant and equipment
Depreciable lives	45 years
Central office and other network electronics
Property, plant and equipment
Property, plant and equipment	$ 3,614	3,362
Central office and other network electronics \| Minimum
Property, plant and equipment
Depreciable lives	4 years
Central office and other network electronics \| Maximum
Property, plant and equipment
Depreciable lives	10 years
Support assets
Property, plant and equipment
Property, plant and equipment	$ 2,584	2,496
Support assets \| Minimum
Property, plant and equipment
Depreciable lives	5 years
Support assets \| Maximum
Property, plant and equipment
Depreciable lives	30 years
Construction in progress
Property, plant and equipment
Property, plant and equipment	$ 273	$ 309

Property, Plant and Equipment (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, plant and equipment
Impairment of real estate	$ 0	$ (17)	$ 0
Office Building
Property, plant and equipment
Impairment of real estate		$ (17)

Severance (Details) - Employee severance - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Restructuring reserve
Balance at the beginning of the period	$ 10	$ 5
Accrued to expense	51	44
Payments, net	(55)	(39)
Balance at the end of the period	$ 6	$ 10

Employee Benefits (Details) $ in Millions	1 Months Ended	12 Months Ended
Employee Benefits (Details) $ in Millions	Oct. 31, 2013	Dec. 31, 2015 USD ($) Employee	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Employee Benefits
Collective bargaining arrangement, number of participating unionized employees \| Employee		11,000
Collective bargaining arrangement, number of participating active employees and retirees \| Employee		11,000
Collective bargaining agreements term	4 years
Qwest Communications International, Inc.
Employee Benefits
Description of related party transaction		In 2015, we agreed to a plan to settle the outstanding affiliate obligations, net balance with QCII over a 30 year term. Payments will be made on a monthly basis.
Repayments on affiliate obligation		$ 105
Allocated expenses by parent entities (as a percent)			92.00%	91.00%
CenturyLink, Inc.
Employee Benefits
Allocated expenses by parent entities (as a percent)		69.00%
Pension Plan
Employee Benefits
Net periodic benefit cost		$ 57	$ (98)	$ (178)
Pension Plan \| CenturyLink, Inc.
Employee Benefits
Employer contributions to benefit plan		100
Unfunded status		(2,207)	(2,402)
Post-Retirement Benefit Plan
Employee Benefits
Net periodic benefit cost		17	128	$ 88
Post-Retirement Benefit Plan \| CenturyLink, Inc.
Employee Benefits
Employer contributions to benefit plan		0
Unfunded status		$ (3,374)	$ (3,477)
Pension, Supplemental and Other Postretirement Benefit Plans \| Qwest Communications International, Inc.
Employee Benefits
Description of related party transaction		In 2015, we agreed to a plan to settle the outstanding pension and post-retirement affiliate obligations, net balance with QCII over a 30 year term. Payments will be made on a monthly basis.
Repayments on affiliate obligation		$ 105
Change in accounting method accounted for as change in estimate \| Pension, Supplemental and Other Postretirement Benefit Plans
Employee Benefits
Decrease in defined benefit plans net periodic benefit cost (financial effect)		The change in methodology resulted in a decrease of $7 million to our net periodic benefit cost for the year ended December 31, 2015
Net periodic benefit cost		$ (7)

Employee Benefits (Details 2) - USD ($) $ in Millions	12 Months Ended
Employee Benefits (Details 2) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Health Care and Life Insurance [Abstract]
Health care benefit expenses	$ 217	$ 204	$ 223

Employee Benefits (Details 3) - USD ($) $ in Millions	12 Months Ended
Employee Benefits (Details 3) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Costs recognized for 401(k) Plan	$ 43	$ 47	$ 49

Share-Based Compensation (Details) - Stock compensation plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based compensation
Share based compensation expense	$ 21	$ 21	$ 17
Income tax benefit recognized, associated with share-based compensation expense	$ 8	$ 8	$ 7

Products and Services Revenues (Details) $ in Millions	3 Months Ended								12 Months Ended
Products and Services Revenues (Details) $ in Millions	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) category segment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Products and Services Revenues
Number of categories of products and services (categories) \| category									3
Operating revenues	$ 2,238	$ 2,287	$ 2,222	$ 2,217	$ 2,223	$ 2,198	$ 2,206	$ 2,211	$ 8,964	$ 8,838	$ 8,753
Taxes and surcharges included in operating revenues and expenses									$ 147	151	154
Number of reportable segments \| segment									1
Operating revenues \| Customer concentration risk
Products and Services Revenues
Concentration risk, percentage									10.00%
Strategic services
Products and Services Revenues
Operating revenues									$ 3,433	3,429	3,342
Legacy services
Products and Services Revenues
Operating revenues									2,777	2,987	3,208
Affiliates and other services
Products and Services Revenues
Operating revenues									$ 2,754	$ 2,422	$ 2,203

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Contingency [Line Items]
Liabilities recorded for interest related to uncertain tax positions					$ 0					$ 0	$ 0
Liabilities recorded for penalties related to uncertain tax positions					0					0	0
Current tax provision:
Federal and foreign									$ 734	738	653
State and local									114	129	101
Total current tax provision									848	867	754
Deferred tax expense:
Federal and foreign									(170)	(209)	(125)
State and local									(19)	(19)	(27)
Total deferred tax expense									(189)	(228)	(152)
Income tax expense	$ 169	$ 171	$ 152	$ 167	161	$ 156	$ 162	$ 160	$ 659	$ 639	$ 602
Effective income tax rate:
Federal statutory income tax rate (as a percent)									35.00%	35.00%	35.00%
State income taxes-net of federal effect (as a percent)									3.60%	4.00%	3.10%
Other (as a percent)									(0.60%)	0.70%	0.30%
Effective income tax rate (as a percent)									38.00%	39.70%	38.40%
Deferred tax liabilities:
Property, plant and equipment	(1,431)				(1,380)				$ (1,431)	$ (1,380)
Intangibles assets	(1,153)				(1,449)				(1,153)	(1,449)
Receivable from an affiliate due to pension plan participation	(460)				(500)				(460)	(500)
Other	(59)				(52)				(59)	(52)
Total deferred tax liabilities	(3,103)				(3,381)				(3,103)	(3,381)
Deferred tax assets:
Payable to affiliate due to post-retirement plan participation	921				998				921	998
Debt premiums	21				36				21	36
Other	277				274				277	274
Total deferred tax assets	1,219				1,308				1,219	1,308
Valuation allowance on deferred tax assets	(12)				(12)				(12)	(12)
Net deferred tax assets	1,207				1,296				1,207	1,296
Net deferred tax liabilities	(1,896)				$ (2,085)				(1,896)	$ (2,085)
Domestic tax authority
Income Tax Contingency [Line Items]
Liabilities recorded for interest related to uncertain tax positions	0								0
Liabilities recorded for penalties related to uncertain tax positions	$ 0								$ 0

Income Taxes (Details 2) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Details 2) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
QSC
Related Party Transaction [Line Items]
Income taxes paid	$ 848	$ 861	$ 750

Fair Value Disclosure (Details) - Fair value, measurements, recurring - Fair value inputs, Level 2 - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Carrying amount
Liabilities
Liabilities-Long-term debt (excluding capital lease and other obligations)	$ 7,222	$ 7,237
Fair value
Liabilities
Liabilities-Long-term debt (excluding capital lease and other obligations)	$ 7,456	$ 7,702

Stockholder's Equity (Details) - USD ($) $ in Millions	12 Months Ended
Stockholder's Equity (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stockholder's Equity (Deficit)
Dividends declared to QSC	$ 1,350	$ 1,400	$ 1,325
Common stock, shares issued (shares)	1	1
Common stock, shares outstanding (shares)	1	1
Dividends
Cash dividend paid to QSC	$ 1,350	$ 1,400	$ 1,325
COMMON STOCK
Stockholder's Equity (Deficit)
Common stock, shares issued (shares)	1
Common stock, shares outstanding (shares)	1

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Operating revenues	$ 2,238	$ 2,287	$ 2,222	$ 2,217	$ 2,223	$ 2,198	$ 2,206	$ 2,211	$ 8,964	$ 8,838	$ 8,753
Operating income	622	572	521	545	496	528	546	542	2,260	2,112	2,078
Income tax expense	169	171	152	167	161	156	162	160	659	639	602
Net income	321	268	$ 238	$ 247	$ 216	$ 245	$ 256	$ 253	$ 1,074	$ 970	$ 964
Incremental increase in other operating revenues - CAF Phase II	$ 31	$ 64

Commitments and Contingencies Commitments and Contingencies (Details)	12 Months Ended
	Dec. 31, 2015 USD ($)
Loss Contingencies [Line Items]
Number of patents allegedly Infringed, minimum	1
Unfavorable regulatory action
Loss Contingencies [Line Items]
Maximum possible loss per proceeding	$ 100,000

Commitments and Contingencies (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Leases, Capital
Assets acquired through capital leases	$ 10	$ 3	$ 0
Depreciation expense	19	32	42
Cash payments towards capital leases	20	32	$ 40
Assets included in property, plant and equipment	66	137
Accumulated depreciation	55	$ 108
Capital lease obligations:
2016	8
2017	4
2018	4
2019	2
2020	0
2021 and thereafter	5
Total minimum payments	23
Less: amount representing interest and executory costs	(7)
Present value of minimum payments	16
Less: current portion	(6)
Long-term portion	$ 10

Commitments and Contingencies (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Leases, Operating
Operating leases, rent expense	$ 75	$ 79	$ 83
Sublease rental income received	4	$ 4	$ 4
Operating leases:
2016	56
2017	50
2018	45
2019	37
2020	32
2021 and thereafter	52
Total future minimum payments	272
Minimum sublease rentals due in the future under non-cancelable subleases	30
Purchase Obligations
Total purchase commitments	132
2016	73
2017 through 2018	53
2019 through 2020	6
2021 and thereafter	$ 0

Other Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 46	$ 45
Other	77	80
Total other current assets	123	125
Accounts Payable, Current [Abstract]
Accounts payable	369	464
Capital expenditures incurred but not yet paid	$ 29	$ 44

Labor Union Contracts (Details)	12 Months Ended
Labor Union Contracts (Details)	Dec. 31, 2015 Employee
Labor Union Contracts
Collective bargaining arrangement, number of participating unionized employees	11,000
Unionized Employees Concentration Risk [Member] \| Employees covered under collective bargaining agreements
Labor Union Contracts
Concentration risk, percentage	50.00%

As of December 31,

(Dollars in millions)

Accounts payable