SPIRIT AIRLINES, INC., 10-K filed on 3/3/2025
Annual Report
v3.25.0.1
Cover - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2024
Feb. 19, 2025
Jun. 28, 2024
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2024    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-35186    
Entity Registrant Name Spirit Airlines, Inc.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 38-1747023    
Entity Address, Address Line One 1731 Radiant Drive    
Entity Address, City or Town Dania Beach    
Entity Address, State or Province FL    
Entity Address, Postal Zip Code 33004    
City Area Code 954    
Local Phone Number 447-7920    
Title of 12(b) Security Common Stock, $0.0001 par value    
Trading Symbol SAVE    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 0.4
Entity Common Stock, Shares Outstanding   109,525,063  
Documents Incorporated by Reference
Portions of the registrant's Proxy Statement for the registrant's 2025 Annual Meeting of Stockholders are incorporated by reference into Part III of this Form 10-K to the extent stated herein. The Proxy Statement will be filed within 120 days of the registrant's fiscal year ended December 31, 2024.
    
Entity Central Index Key 0001498710    
Amendment Flag false    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2024    
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Audit Information
 12 Months Ended
Dec. 31, 2024
Audit Information [Abstract]  
Auditor Firm ID 42
Auditor Name Ernst & Young, LLP
Auditor Location Miami, FL
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Consolidated Statements Of Operations - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Operating revenues:      
Total operating revenues $ 4,913,421,000 $ 5,362,549,000 $ 5,068,447,000
Operating expenses:      
Salaries, wages and benefits 1,689,083,000 1,616,803,000 1,251,225,000
Aircraft fuel 1,479,203,000 1,821,165,000 1,929,969,000
Aircraft rent 541,909,000 381,239,000 282,428,000
Landing fees and other rents 451,008,000 408,262,000 347,268,000
Depreciation and amortization 325,273,000 320,872,000 313,090,000
Maintenance, materials and repairs 217,738,000 223,339,000 187,820,000
Distribution 197,197,000 190,891,000 177,557,000
Special charges (credits) 36,029,000 69,537,000 420,172,000
Loss (gain) on disposal of assets 273,871,000 33,966,000 46,624,000
Other operating 807,488,000 792,232,000 711,211,000
Total operating expenses 6,018,799,000 5,858,306,000 5,667,364,000
Operating income (loss) (1,105,378,000) (495,757,000) (598,917,000)
Other (income) expense:      
Interest expense 219,094,000 169,191,000 139,905,000
Loss (gain) on extinguishment of debt (14,937,000) (15,411,000) 0
Capitalized interest (18,087,000) (33,360,000) (22,818,000)
Interest income (48,324,000) (61,647,000) (20,083,000)
Other (income) expense (65,694,000) 4,065,000 4,818,000
Special charges, non-operating 15,493,000 0 0
Reorganization expense 96,780,000 0 0
Total other (income) expense 184,325,000 62,838,000 101,822,000
Income (loss) before income taxes (1,289,703,000) (558,595,000) (700,739,000)
Provision (benefit) for income taxes (60,208,000) (111,131,000) (146,589,000)
Net income (loss) $ (1,229,495,000) $ (447,464,000) $ (554,150,000)
Basic earnings (loss) per share ( in dollars per share) $ (11.23) $ (4.10) $ (5.10)
Diluted earning (loss) per share ( in dollars per share) $ (11.23) $ (4.10) $ (5.10)
Passenger      
Operating revenues:      
Total operating revenues $ 4,811,752,000 $ 5,268,161,000 $ 4,989,365,000
Other      
Operating revenues:      
Total operating revenues $ 101,669,000 $ 94,388,000 $ 79,082,000
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Consolidated Statements of Comprehensive Income (Loss) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Statement of Comprehensive Income [Abstract]      
Net income (loss) $ (1,229,495) $ (447,464) $ (554,150)
Unrealized gain (loss) on short-term investment securities and cash and cash equivalents, net of deferred taxes of $(32), $84 and $(65) 169 287 (216)
Interest rate derivative loss reclassified into earnings, net of taxes of $17, $72 and $47 86 242 152
Other comprehensive income (loss) 255 529 (64)
Comprehensive income (loss) $ (1,229,240) $ (446,935) $ (554,214)
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Consolidated Statements of Comprehensive Income (Loss) (Parentheticals) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Statement of Comprehensive Income [Abstract]      
Tax effect of the unrealized gain (loss) on short-term investment securities and cash and cash equivalents $ (32) $ 84 $ (65)
Tax effect of interest rate derivative loss reclassified into earnings $ 17 $ 72 $ 47
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Consolidated Balance Sheets - USD ($)
$ in Thousands
Dec. 31, 2024
Dec. 31, 2023
Current assets:    
Cash and cash equivalents $ 902,057 $ 865,211
Restricted cash 168,390 119,400
Short-term investment securities 118,334 112,501
Accounts receivable, net 178,955 205,468
Prepaid expenses and other current assets 278,366 207,700
Assets held for sale 463,020 1,847
Total current assets 2,109,122 1,512,127
Property and equipment:    
Flight equipment 2,736,461 3,961,785
Other property and equipment 784,195 726,364
Less accumulated depreciation (1,027,872) (1,169,021)
Total property and equipment 2,492,784 3,519,128
Operating lease right-of-use assets 4,583,734 3,561,028
Pre-delivery deposits on flight equipment 113,493 480,717
Deferred heavy maintenance, net 241,094 313,505
Other long-term assets 54,951 30,732
Total assets 9,595,178 9,417,237
Current liabilities:    
Accounts payable 32,385 42,098
Air traffic liability 436,813 383,751
Current maturities of long-term debt, net, and finance leases 436,532 315,580
Current maturities of operating leases 257,796 224,865
Other current liabilities 605,839 705,298
Total current liabilities 1,769,365 1,671,592
Long-term debt and finance leases, less current maturities 1,761,215 3,055,221
Operating leases, less current maturities 4,335,106 3,298,871
Deferred income taxes 51,927 107,761
Deferred gains and other long-term liabilities 122,595 149,450
Liabilities subject to compromise 1,635,104 0
Shareholders’ equity (deficit):    
Common stock: Common stock, $0.0001 par value, 240,000,000 shares authorized at December 31, 2024 and 2023, respectively; 111,661,332 and 111,303,660 issued and 109,525,063 and 109,263,005 outstanding as of December 31, 2024 and 2023, respectively 11 11
Additional paid-in-capital 1,173,692 1,158,278
Treasury stock, at cost: 2,136,269 and 2,040,655 as of December 31, 2024 and 2023, respectively (81,285) (80,635)
Retained earnings (deficit) (1,172,740) 56,755
Accumulated other comprehensive income (loss) 188 (67)
Total shareholders’ equity (deficit) (80,134) 1,134,342
Total liabilities and shareholders’ equity (deficit) $ 9,595,178 $ 9,417,237
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Consolidated Balance Sheets (Parenthetical) - $ / shares
Dec. 31, 2024
Dec. 31, 2023
Statement of Financial Position [Abstract]    
Common stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 240,000,000 240,000,000
Common stock, shares issued (in shares) 111,661,332 111,303,660
Common stock, shares outstanding (in shares) 109,525,063 109,263,005
Treasury stock (in shares) 2,136,269 2,040,655
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Consolidated Statements of Cash Flows - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Operating activities:      
Net income (loss) $ (1,229,495,000) $ (447,464,000) $ (554,150,000)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operations:      
Losses reclassified from other comprehensive income 103,000 314,000 199,000
Share-based compensation 7,210,000 11,963,000 11,483,000
Allowance for doubtful accounts (recoveries) 822,000 159,000 (108,000)
Amortization of debt issuance costs 13,100,000 15,454,000 13,468,000
Depreciation and amortization 325,273,000 320,872,000 313,090,000
Accretion of convertible debt and 8.00% senior secured notes 3,821,000 4,210,000 1,421,000
Amortization of debt discount 10,156,000 8,145,000 13,962,000
Deferred income tax benefit (58,215,000) (119,239,000) (148,611,000)
Fixed asset impairment charges 0 0 333,691,000
Loss (gain) on disposal of assets 273,871,000 33,966,000 46,624,000
Reorganization expense 85,554,000 0 0
Changes in operating assets and liabilities:      
Accounts receivable, net 26,797,000 (8,351,000) (68,340,000)
Deposits and other assets (76,744,000) 4,215,000 (28,883,000)
Deferred heavy maintenance (86,412,000) (202,926,000) (149,287,000)
Income tax receivable (96,000) 36,261,000 1,629,000
Accounts payable (40,124,000) (34,051,000) 9,032,000
Air traffic liability 53,062,000 (45,867,000) 47,301,000
Other liabilities (63,688,000) 176,440,000 68,389,000
Other (3,082,000) (762,000) 68,000
Net cash provided by (used in) operating activities (758,087,000) (246,661,000) (89,022,000)
Investing activities:      
Purchase of available-for-sale investment securities (161,745,000) (127,627,000) (110,690,000)
Proceeds from the maturity and sale of available-for-sale investment securities 160,350,000 125,570,000 109,500,000
Proceeds from sale of property and equipment 232,564,000 230,788,000 0
Pre-delivery deposit and other payments on flight equipment (6,471,000) (86,245,000) (188,908,000)
Pre-delivery deposit refunds on flight equipment 362,765,000 109,401,000 180,410,000
Capitalized interest (14,475,000) (21,860,000) (18,166,000)
Assets under construction for others 1,568,000 (10,972,000) (2,000)
Purchase of property and equipment (110,955,000) (255,563,000) (237,584,000)
Net cash provided by (used in) investing activities 463,601,000 (36,508,000) (265,440,000)
Financing activities:      
Proceeds from issuance of long-term debt 423,500,000 457,950,000 591,000,000
Proceeds from DIP financing 300,000,000 0 0
Payments on debt obligations (185,446,000) (337,475,000) (193,033,000)
Payments for the early extinguishment of debt (140,679,000) (323,251,000) 0
Payments on finance lease obligations (312,000) (496,000) (842,000)
Reimbursement for assets under construction for others (1,568,000) 10,974,000 2,000
Repurchase of common stock (650,000) (2,637,000) (2,359,000)
Debt and equity financing costs (14,523,000) (3,027,000) (3,471,000)
Net cash provided by (used in) financing activities 380,322,000 (197,962,000) 391,297,000
Net increase (decrease) in cash, cash equivalents, and restricted cash 85,836,000 (481,131,000) 36,835,000
Cash, cash equivalents, and restricted cash at beginning of period [1] 984,611,000 1,465,742,000 1,428,907,000
Cash, cash equivalents, and restricted cash at end of period [1] 1,070,447,000 984,611,000 1,465,742,000
Cash payments for:      
Interest, net of capitalized interest 176,187,000 138,380,000 107,443,000
Income taxes paid (received), net 3,548,000 (32,854,000) (82,000)
Cash paid for amounts included in the measurement of lease liabilities:      
Operating cash flows for operating leases 532,499,000 400,999,000 295,468,000
Financing cash flows for finance leases 33,000 30,000 57,000
Non-cash transactions:      
Capital expenditures funded by finance lease borrowings 274,000 145,000 0
Capital expenditures funded by operating lease borrowings $ 1,312,237,000 $ 1,076,456,000 $ 897,109,000
[1] The sum of cash and cash equivalents and restricted cash on the consolidated balance sheets equals cash, cash equivalents, and restricted cash in the consolidated statements of cash flows.
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Consolidated Statements of Cash Flows (Parenthetical)
Dec. 31, 2024
Nov. 18, 2024
8.00% senior secured notes | 8.00% senior secured notes due in 2025    
Stated interest rate percentage 8.00% 8.00%
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Consolidated Statements of Shareholders’ Equity (Deficit) - USD ($)
$ in Thousands
Total
Common Stock
Additional Paid-In Capital
Treasury Stock
Retained Earnings
Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2021 $ 2,114,035 $ 11 $ 1,131,826 $ (75,639) $ 1,058,369 $ (532)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Convertible debt conversions 2,706   2,706      
Share-based compensation 11,483   11,483      
Repurchase of common stock (2,359)     (2,359)    
Changes in comprehensive income (loss) (64)         (64)
Net income (loss) (554,150)       (554,150)  
Ending balance at Dec. 31, 2022 1,571,651 11 1,146,015 (77,998) 504,219 (596)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Convertible debt conversions 300   300      
Share-based compensation 11,963   11,963      
Repurchase of common stock (2,637)     (2,637)    
Changes in comprehensive income (loss) 529         529
Net income (loss) (447,464)       (447,464)  
Ending balance at Dec. 31, 2023 1,134,342 11 1,158,278 (80,635) 56,755 (67)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Share-based compensation 7,210   7,210      
Repurchase of common stock (650)     (650)    
Derivative liability 8,204   8,204      
Changes in comprehensive income (loss) 255         255
Net income (loss) (1,229,495)       (1,229,495)  
Ending balance at Dec. 31, 2024 $ (80,134) $ 11 $ 1,173,692 $ (81,285) $ (1,172,740) $ 188
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Summary of Significant Accounting Policies
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies Summary of Significant Accounting Policies
Basis of Presentation
The accompanying consolidated financial statements include the accounts of Spirit Airlines, Inc. ("Spirit") and its consolidated subsidiaries (the "Company"). Spirit is headquartered in Dania Beach, Florida, offers affordable travel to value-conscious customers and serves destinations throughout the United States, Latin America and the Caribbean. Spirit manages operations on a system-wide basis due to the interdependence of its route structure in the various markets served.
The classification of certain prior year amounts have been adjusted on the Company's consolidated financial statements and these Notes to conform to current year classifications.

On November 18, 2024 (the “Petition Date”), Spirit commenced a voluntary case (the “Chapter 11 Case”) under Chapter 11 of Title 11 of the United States Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Southern District of New York (the “Bankruptcy Court”), and, on November 25, 2024, its subsidiaries also filed voluntary petitions seeking relief under Chapter 11 of the Bankruptcy Code and joined the Chapter 11 Case (collectively, the “Chapter 11 Cases”). The filing of the Chapter 11 Cases constituted defaults, termination events and/or amortization events with respect to certain of the Company's existing debt obligations.

Upon emergence, the Company expects to adopt fresh start accounting in accordance with ASC 852, Reorganizations. Under fresh start accounting rules, as of the Effective Date of the Plan, the Company’s assets and liabilities will be adjusted to fair value and its accumulated deficit will be restated to zero, which the Company expects will result in material adjustments to the recorded value of certain of its assets and liabilities. As a result, the Company may incur higher depreciation and amortization expense following the Effective Date. In addition, the Company may adopt accounting policy changes as part of fresh start accounting and such policies could result in material changes to its financial reporting and results. The actual impact of the application of fresh start accounting and any such accounting policy changes will be determined by management upon and following the Effective Date. As a result of the application of fresh start accounting and the effects of the implementation of the Plan, the Company expects that its financial condition and results of operations following the Chapter 11 Emergence will not be comparable to the financial condition and results of operations reflected in its historical financial statements.

Going Concern

The Company’s consolidated financial statements have been prepared assuming that it will continue as a going concern, which contemplates continuity of operations, realization of assets and liquidation of liabilities in the normal course of business. During the Chapter 11 Cases, the Company’s ability to continue as a going concern is contingent upon the Company’s ability to successfully implement the Company’s Plan, among other factors.
The Company has been impacted by an increasingly challenging pricing environment. Moreover, the expected short-term impact of certain policy changes, such as the removal of change and cancel fees, have negatively affected revenue performance. In addition, challenging market conditions, including increasing costs, have impacted the Company's performance.

In addition, the Company had been in discussions with representatives of certain of its bondholders to negotiate the terms for refinancing or extending its existing 8.00% senior secured notes due in September 2025, as well as representatives of certain of its convertible notes due 2026. On November 18, 2024, the Company entered into a Restructuring Support Agreement (as defined below) with certain of its bondholders.
The Company has evaluated whether there are any conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year from the filing of this Annual Report on Form 10-K. On the “Petition Date”, the Company commenced the Chapter 11 Case under the Bankruptcy Code in the Bankruptcy Court. On November 25, 2024, under the terms of the Restructuring Support Agreement, certain of Spirit’s subsidiaries (together with Spirit, the “Company Parties”) filed voluntary petitions seeking relief under Chapter 11 of the Bankruptcy Code and joined the Chapter 11 Cases. Since the Petition Date, the Company has been operating its businesses as a debtor-in-possession under the jurisdiction of the Bankruptcy Court in accordance with the applicable provisions of the Bankruptcy Code and orders of the Bankruptcy Court. The Company received approval from the Bankruptcy Court for a variety of “first day” motions to continue its ordinary course operations during the Chapter 11 Case. However, for the duration of the Chapter 11 Cases, the Company’s operations and ability to develop and execute its business plan, its financial condition, liquidity and its continuation as a going concern are subject to a high degree of risk and uncertainty associated with the Chapter 11 Cases. The outcome of the Chapter 11 Cases is dependent upon factors that are outside of the Company’s control, including actions of the
Bankruptcy Court. The Company can give no assurances that it will be able to secure additional sources of funds to support its operations, or, if such funds are available to the Company, that such additional financing will be sufficient to meet its needs. Based on such evaluation and management’s current plans, which are subject to change and include implementation of discretionary cost reduction strategies and the sale of certain of its owned aircraft, management believes there is substantial doubt about the Company’s ability to continue as a going concern.
Use of Estimates
The preparation of financial statements in accordance with generally accepted accounting principles in the United States of America requires the Company's management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. The Company's estimates and assumptions are based on historical experience and changes in the business environment. However, actual results may differ from estimates under different conditions, sometimes materially.
Cash and Cash Equivalents
The Company considers all highly liquid investments with maturities of less than three months at the date of acquisition to be cash equivalents. Investments included in this category primarily consist of cash and money market funds. Cash and cash equivalents are stated at cost, which approximates fair value.
Restricted Cash
The Company's restricted cash is comprised of cash held in an account subject to a control agreement to be used for the payment of interest and fees on the Company's 8.00% senior secured notes, cash held in an account subject to a control agreement under its credit card processing agreement, pledged cash pursuant to its corporate credit cards and cash pledged as collateral against the Company's standby letters of credit.
Short-term Investment Securities
The Company's short-term investment securities are classified as available-for-sale and generally consist of U.S. Treasury and U.S. government agency securities with contractual maturities of twelve months or less. The Company's short-term investment securities are categorized as Level 1 instruments, as the Company uses quoted market prices in active markets when determining the fair value of these securities. For additional information, refer to Note 8, Short-term Investment Securities. These securities are stated at fair value within current assets on the Company's consolidated balance sheet. For all short-term investments, at each reset period or upon reinvestment, the Company accounts for the transaction as proceeds from the maturity of short-term investment securities for the security relinquished, and purchase of short-term investment securities for the security purchased, in the Company's consolidated statements of cash flows. Realized gains and losses on sales of investments, if any, are reflected in non-operating other (income) expense in the consolidated statements of operations. Unrealized gains and losses on investment securities are reflected as a component of accumulated other comprehensive income.
Accounts Receivable
Accounts receivable primarily consist of amounts due from credit card processors associated with the sales of tickets, amounts due from the Internal Revenue Service related to federal excise fuel tax and amounts expected to be received related to the CARES Employee Retention credit. The Company records an allowance for amounts not expected to be collected. The Company estimates the allowance based on historical write-offs and aging trends as well as an estimate of the expected lifetime credit losses. The allowance for doubtful accounts was immaterial as of December 31, 2024 and 2023.
In addition, the provision for doubtful accounts and write-offs for 2024, 2023 and 2022 were each immaterial.
Property and Equipment
Property and equipment is stated at cost, less accumulated depreciation and amortization. Depreciation of operating property and equipment is computed using the straight-line method applied to each unit of property. Residual values for new aircraft, new engines, major spare rotable parts, avionics and assemblies are generally estimated to be 10%. Property under finance leases and related obligations are initially recorded at an amount equal to the present value of future minimum lease payments computed using the Company's incremental borrowing rate or, when known, the interest rate implicit in the lease. Amortization of property under finance leases is recorded on a straight-line basis over the lease term and is included in depreciation and amortization expense.
The depreciable lives used for the principal depreciable asset classifications are:
 Estimated Useful Life
Aircraft, engines and flight simulators
25
Spare rotables and flight assemblies
7 to 25 years
Other equipment and vehicles
5 to 7 years
Internal use software
3 to 10 years
Finance leasesLease term or estimated useful life of the asset
Leasehold improvementsLesser of lease term or estimated useful life of the improvement
Buildings
Lesser of lease term or 40 years
As of December 31, 2024, the Company had 46 aircraft (including 18 aircraft that would have been deemed finance leases resulting in failed sale leaseback transactions and excluding 21 aircraft recorded as assets held for sale on its consolidated balance sheets as of December 31, 2024), 32 spare engines and 4 flight simulators capitalized within flight equipment with depreciable lives of 25 years.
During the fourth quarter of 2019, the Company purchased an 8.5-acre parcel of land for $41.0 million and entered into a 99-year lease agreement for the lease of a 2.6-acre parcel of land, in Dania Beach, Florida, where the Company built its new headquarters campus and a 200-unit residential building. As of December 31, 2024, the 8.5-acre parcel of land and related construction costs were capitalized within other property and equipment on the Company's consolidated balance sheets. The 99-year lease was determined to be an operating lease and is recorded within operating lease right-of-use asset and operating lease liability on the Company's consolidated balance sheets.
    The following table illustrates the components of depreciation and amortization expense:
 Year Ended December 31,
202420232022
(in thousands)
Depreciation$177,872 $218,106 $199,118 
Amortization of heavy maintenance113,522 79,768 96,707 
Amortization of capitalized software33,879 22,998 17,265 
Total depreciation and amortization$325,273 $320,872 $313,090 
The Company capitalizes certain internal and external costs associated with the acquisition and development of internal-use software for new products, and enhancements to existing products, that have reached the application development stage and meet recoverability tests. Capitalized costs include external direct costs of materials and services utilized in developing or obtaining internal-use software, and labor cost for employees who are directly associated with, and devote time, to internal-use software projects. Capitalized computer software, included as a component of other property and equipment in the accompanying consolidated balance sheets, net of amortization, was $48.8 million and $53.6 million at December 31, 2024 and 2023, respectively.
The Company records amortization of capitalized software on a straight-line basis within depreciation and amortization expense in the accompanying consolidated statements of operations. The Company placed in service internal-use software of $29.2 million, $35.5 million and $25.7 million, during the years ended 2024, 2023 and 2022, respectively.
Deferred Heavy Maintenance, net
The Company accounts for heavy maintenance and major overhaul under the deferral method whereby the cost of heavy maintenance is capitalized and amortized as a component of depreciation and amortization expense in the consolidated statements of operations until the earlier of the next heavy maintenance event or the end of the lease term. Deferred heavy maintenance, net was $241.1 million and $313.5 million at December 31, 2024 and 2023, respectively.
Operating Lease Right-of-Use Asset and Liabilities
Right-of-use assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. When available, the Company uses the rate implicit in the lease to discount lease payments to present value. However, the Company's
leases generally do not provide a readily determinable implicit rate. Therefore, the Company estimates the incremental borrowing rate to discount lease payments based on information available at lease commencement. The Company uses publicly available data for instruments with similar characteristics when calculating its incremental borrowing rates. The Company has options to extend certain of its operating leases for an additional period of time and options to early terminate several of its operating leases. The lease term consists of the noncancellable period of the lease, periods covered by options to extend the lease if the Company is reasonably certain to exercise the option and periods covered by an option to terminate the lease if the Company is reasonably certain not to exercise the option. The Company's lease agreements do not contain any residual value guarantees. The Company elected to not separate non-lease components from the associated lease component for all underlying classes of assets with lease and non-lease components.
The Company elected not to apply the recognition requirements in Topic 842 to short-term leases (i.e., leases of 12 months or less) but instead recognize these lease payments in income on a straight-line basis over the lease term. The Company elected this accounting policy for all classes of underlying assets. In addition, in accordance with Topic 842, variable lease payments are not included in the recognition of a lease liability or right-of-use asset.
Pre-Delivery Deposits on Flight Equipment
The Company is required to make pre-delivery deposit payments ("PDPs") towards the purchase price of each new aircraft and engine prior to the scheduled delivery date. These deposits are initially classified as pre-delivery deposits on flight equipment on the Company's consolidated balance sheets until the aircraft or engine is delivered, at which time the related PDPs are deducted from the final purchase price of the aircraft or engine and are reclassified to flight equipment on the Company's consolidated balance sheets. The Company may also be entitled to refunds of PDPs resulting from sale leaseback transactions for aircraft previously included in the Company’s order book, as well as any agreements that modify the timing of aircraft deliveries or involve the removal of aircraft from its order book. For additional information on transactions entered into by the Company in 2024 that provided PDP refunds, refer to Note 17, Commitments and Contingencies.
In addition, the Company capitalizes the interest that is attributable to the outstanding PDP balances as a percentage of the related debt on which interest is incurred. Capitalized interest represents interest cost incurred during the acquisition period of a long-term asset and is the amount which theoretically could have been avoided had the Company not paid PDPs for the related aircraft or engines.
Related interest is capitalized and included within pre-delivery deposits on flight equipment through the acquisition period until delivery is taken of the aircraft or engine and the asset is ready for service. Once the aircraft or engine is delivered, the capitalized interest is also reclassified into flight equipment on the Company's consolidated balance sheets along with the related PDPs as they are included in the cost of the aircraft or engine. Capitalized interest for 2024, 2023 and 2022 was primarily related to the interest incurred on long-term debt.
Assets Held for Sale
As of December 31, 2024 and 2023, the Company had $463.0 million and $1.8 million, respectively, recorded within assets held for sale in its consolidated balance sheets.
The Company's assets held for sale as of December 31, 2024 primarily consisted of 21 aircraft currently under contract for sale. On October 29, 2024, the Company entered into an aircraft sale and purchase agreement with GA Telesis, LLC (“GAT”) for the sale of 23 A320ceo and A321ceo aircraft to GAT, of which 2 were sold in December 2024. Currently, these aircraft are not being utilized within the operation and are available for immediate sale.
The Company's assets held for sale as of December 31, 2023 primarily consisted of rotable aircraft parts.

During the fourth quarter of 2024, the Company concluded that Management’s plan to early retire and sell the 23 aircraft met the required criteria to be classified as held for sale. As a result, the Company recorded the estimated fair value, less cost to sell, of these aircraft within assets held for sale on its consolidated balance sheets. When long-lived assets are identified as held for sale and the required criteria are met, the Company reclassifies the assets from property and equipment to assets held for sale on the Company's consolidated balance sheets and discontinues depreciation. The fair values were determined using Level 3 fair value inputs primarily based on the agreed upon sales price for each aircraft. Additionally, the Company recognized $282.5 million in impairment-related charges, reflecting the excess of the carrying amount (including related deferred heavy maintenance, net) over the estimated fair value. These impairment charges were recorded within loss (gain) on disposal of assets in the Company’s consolidated statement of operations during 2024. For additional information, refer to Note 5, Loss (Gain) on Disposal of Assets.
Measurement of Asset Impairments
The Company records impairment charges on long-lived assets used in operations when events and circumstances indicate that the assets may be impaired, the undiscounted future cash flows estimated to be generated by those assets are less than the carrying amount of those assets, and the net book value of the assets exceeds their estimated fair value. Factors which could be indicators of impairment include but are not limited to (1) a decision to permanently remove flight equipment or other long-lived assets from operations, (2) significant changes in the estimated useful life, (3) significant changes in projected cash flows, (4) permanent and significant declines in related fair values and (5) changes to the regulatory environment. If an impairment indicator is identified, the Company conducts a recoverability analysis. In performing the analysis, the Company uses certain assumptions, including, but not limited to: (i) estimated fair value of the assets; and (ii) estimated, undiscounted future cash flows expected to be generated by these assets, which are based on additional assumptions such as asset utilization, length of service the asset will be used in the Company’s operations, and estimated salvage values. Depending on the results of the recoverability analysis, an impairment loss is measured as the difference between the asset's carrying value and its fair value.
The Company has determined that indicators of potential impairment, including negative cash flows and its bankruptcy filing during the fourth quarter of 2024, were present as of December 31, 2024. These indicators prompted the Company to perform a recoverability analysis on its assets to assess whether any impairment losses should be recognized. In estimating the undiscounted future cash flows, the Company uses certain assumptions, including, but not limited to, the estimated, undiscounted future cash flows expected to be generated by these assets, estimates of length of service the asset will be used in the Company’s operations and estimated salvage values. The Company assessed whether any impairment of its long-lived assets existed as of December 31, 2024 and has determined that the assets are recoverable. The Company’s assumptions about future conditions important to its assessment of potential impairment of its long-lived assets are subject to uncertainty, and the Company will continue to monitor these conditions in future periods as new information becomes available and will update its analyses accordingly.
During 2023, the Company did not recognize impairment-related charges.
During the fourth quarter of 2022, the Company made the decision to accelerate the retirement of 29 of its A319 aircraft, which were owned and unencumbered, as of December 31, 2022. In January 2023, the Company executed a purchase agreement to sell these aircraft over the next two years. The Company concluded that Management’s plan to early retire and ultimately sell these 29 A319 aircraft is an impairment indicator which required the Company to test the recoverability of the related asset group as of December 31, 2022. No impairment indicators existed and no charges were necessary under applicable accounting standards as of December 31, 2022, for the remaining flight equipment, which together represent one asset group.
The Company concluded that the net book value of this specific asset group of owned A319 aircraft was not recoverable as of December 31, 2022, due to changes to the estimated future cash flows primarily driven by the significant reductions to their remaining operating lives. As a result, during 2022, the Company recognized $333.7 million in impairment-related charges for the amount by which the carrying amount of this asset group, including the related net capitalized maintenance, exceeded its estimated fair value. During 2022, the impairment charges were recorded within special charges (credits) in the Company’s consolidated statement of operations. The fair values of these assets were determined using Level 3 fair value inputs primarily based on the agreed upon sales price for each aircraft, adjusted for estimated utilization in the period of operation from December 31, 2022 to the expected future sales date. For additional information, refer to Note 5, Loss (Gain) on Disposal of Assets.
Passenger Revenues

Operating revenues are comprised of passenger revenues and other revenues. Passenger revenues are primarily comprised of fares and related ancillary items such as bags, seats and other travel-related fees. Other revenues primarily consist of the marketing component of the sale of loyalty points to the Company's credit card partner and commissions revenue from the sale of various items, such as hotels and rental cars.
Passenger revenues are generally recognized once the related flight departs. Accordingly, the value of tickets and ancillary products sold in advance of travel is included under the Company's current liabilities as “air traffic liability,” or “ATL”, until the related air travel is provided. As of December 31, 2024 and December 31, 2023, the Company had ATL balances of $436.8 million and $383.8 million, respectively. Substantially all of the Company's ATL as of December 31, 2024 is expected to be recognized within 12 months of the respective balance sheet date.    
Changes and cancellations. An unused ticket expires at the date of scheduled travel, at which time a service charge is assessed, and is recognized as revenue at the date of scheduled travel. However, customers may elect to change or cancel their itinerary prior to the date of departure. In 2024, the Company launched its no change or cancel fee policy for its bundled travel
options. Guests are required to pay the difference in fare if the new trip is more expensive or receive a credit if the new trip is less expensive.

Any unused amount is placed in a credit shell which generally expires 12 months from the date the credit shell is created. Prior to May 2024, credit shells generally expired 90 days from the date the credit shell was created. Credit shells can be used towards the purchase of a new ticket and the Company’s other service offerings. Credit shell amounts are recorded as deferred revenue and amounts expected to expire unused are estimated based on historical experience.

Estimating the amount of credits that will go unused involves some level of subjectivity and judgment. Assumptions used to generate breakage estimates can be impacted by several factors including, but not limited to, changes to the Company's ticketing policies, changes to the Company’s refund, exchange, and credit shell policies, and economic factors. The amount of credit shells issued varies, primarily due to the flight delays and cancellation events throughout the year. The Company generally experiences some variability in the amount of breakage revenue recognized throughout the year and expects some variability in the amount of breakage revenue recorded in future periods, as the estimates of the portion of those funds that will expire unused may differ from historical experience.

Loyalty Program
    
The Company operates the Spirit Saver$ Club®, which is a subscription-based loyalty program that allows members access to exclusive, extra-low fares, as well as discounted prices on bags and seats, shortcut boarding and security, and exclusive offers on hotels, rental cars and other travel necessities. The Company also operates the Free Spirit loyalty program (the "Free Spirit Program"), which attracts members and partners and builds customer loyalty for the Company by offering a variety of awards, benefits and services. Free Spirit loyalty program members earn and accrue points for dollars spent on Spirit for flights and other non-fare services, as well as services from non-air partners such as retail merchants, hotels or car rental companies. Customers can also earn points based on their spending with the Company's co-branded credit card company with which the Company has an agreement to sell points. The Company's co-branded credit card agreement provides for joint marketing pursuant to which cardholders earn points by making purchases using co-branded cards. Points earned and accrued by Free Spirit loyalty program members can be redeemed for travel awards such as free (other than taxes and government-imposed fees), discounted or upgraded travel. The Company's agreement with the administrator of the Free Spirit affinity credit card program expires on December 31, 2028.
The Company defers the amount of award travel obligations as part of loyalty deferred revenue within ATL on the Company's consolidated balance sheets and recognizes loyalty travel awards in passenger revenues as points are used for travel or expire unused.

    To reflect the point credits earned, the program includes two types of transactions that are considered revenue arrangements with multiple performance obligations: (1) points earned with travel and (2) points sold to its co-branded credit card partner.

    Passenger ticket sales earning points. Passenger ticket sales earning points provide customers with (1) points earned and (2) air transportation. The Company values each performance obligation on a stand-alone basis and allocates the consideration to each performance obligation based on their relative fair value. To value the point credits earned, the Company considers the quantitative value a passenger receives by redeeming points for a ticket rather than paying cash, which is referred to as equivalent ticket value ("ETV").

The Company defers revenue for the points when earned and recognizes loyalty travel awards in passenger revenue as the points are redeemed and services are provided. The Company records the air transportation portion of the passenger ticket sales in air traffic liability and recognizes passenger revenue when transportation is provided or if the ticket goes unused, at the date of scheduled travel.

    Sale of points. Customers may earn points based on their spending with the Company's co-branded credit card company with which the Company has an agreement to sell points. The contract to sell points under this agreement has multiple performance obligations, as discussed below.

The Company's co-branded credit card agreement provides for joint marketing where cardholders earn points for making purchases using co-branded cards. During 2023, the Company extended its agreement with the administrator of the Free Spirit affinity credit card program through December 31, 2028. The Company accounts for this agreement consistently with the accounting method that allocates the consideration received to the individual products and services delivered. The value is
allocated based on the relative stand-alone selling prices of those products and services, which generally consists of (i) points to be awarded, (ii) airline benefits, collectively referred to as the "award travel components," (iii) licensing of brand and access to member lists and (iv) advertising and marketing efforts, collectively referred to as the "marketing components." Revenue allocated to the award travel components are recorded in passenger revenues, while the revenue allocated to the marketing components are recorded in other revenues. The Company determined the estimate of the stand-alone selling prices by considering discounted cash flow analysis using multiple inputs and assumptions, including: (1) the expected number of points awarded and number of points redeemed, (2) the estimated stand-alone selling price of the award travel obligation and airline benefits, (3) licensing of brand access to member lists and (4) the cost of advertising and marketing efforts undertaken by the Company.

The Company defers the amount for award travel obligation as part of loyalty deferred revenue. These amounts that are expected to be redeemed during the following twelve months are recorded within ATL on the Company's consolidated balance sheet and the portion that is expected to be redeemed beyond the following twelve months is recorded within long-term liabilities on the consolidated balance sheet. In addition, the Company recognizes loyalty travel awards in passenger revenue as the points are used for travel. Revenue allocated to the marketing components are recorded in other revenue as points are delivered. Total unrecognized revenue from future Free Spirit Program was $101.5 million and $104.6 million at December 31, 2024 and 2023, respectively. The current portion of this balance is recorded within air traffic liability and the long-term portion of this balance is recorded within deferred gains and other long-term liabilities in the accompanying consolidated balance sheets.
    The following table illustrates total cash proceeds received from the sale of points and the portion of such proceeds recognized in passenger revenue immediately as marketing component:
Consideration received from credit card loyalty programsPortion of proceeds recognized immediately as marketing component
Year Ended(in thousands)
December 31, 2024$85,812 $51,220 
December 31, 202393,147 48,071 
December 31, 202280,970 40,987 

    Points breakage. For points that the Company estimates are not likely to be redeemed ("breakage"), the Company recognizes the associated value proportionally during the period in which the remaining points are redeemed. Management uses statistical models to estimate breakage based on historical redemption patterns. A change in assumptions as to the period over which points are expected to be redeemed, the actual redemption activity for points or the estimated fair value of points expected to be redeemed could have an impact on revenues in the year in which the change occurs and in future years.

    Current activity of loyalty program. Points are combined in one homogeneous pool and are not separately identifiable. As such, revenue is composed of points that were part of the loyalty deferred revenue balance at the beginning of the period as well as points that were issued during the period.

Other Revenues

Other revenues primarily consist of the marketing component of the sale of loyalty points to the Company's credit card partner and commissions revenue from the sale of various items such as hotels and rental cars.
Airframe and Engine Maintenance
The Company accounts for heavy maintenance and major overhaul under the deferral method whereby the cost of heavy maintenance and major overhaul is deferred and amortized until the earlier of the end of the useful life of the related asset, the end of the remaining lease term or the next scheduled heavy maintenance event.
Amortization of heavy maintenance and major overhaul costs charged to depreciation and amortization expense was $113.5 million, $79.8 million and $96.7 million for the years ended 2024, 2023 and 2022, respectively. During the years ended 2024, 2023 and 2022, the Company deferred $86.4 million, $202.9 million and $149.3 million, respectively, of costs for heavy maintenance. As of December 31, 2024 and 2023, the Company had a deferred heavy maintenance balance of $577.3 million and $529.8 million, and accumulated heavy maintenance amortization of $273.8 million and $216.2 million, respectively.
The Company outsources certain routine, non-heavy maintenance functions under contracts that require payment on a utilization basis, primarily based on flight hours. Costs incurred for maintenance and repair under flight hour maintenance contracts, where labor and materials price risks have been transferred to the service provider, are expensed based on contractual payment terms. All other costs for routine maintenance of the airframes and engines are charged to expense as performed.
The table below summarizes the components of the Company’s maintenance cost:
 Year Ended December 31,
202420232022
(in thousands)
Utilization-based maintenance expense$103,232 $117,458 $97,930 
Non-utilization-based maintenance expense114,506 105,881 89,890 
Total maintenance, materials and repairs$217,738 $223,339 $187,820 
Leased Aircraft Return Costs
The Company's aircraft lease agreements often contain provisions that require the Company to return aircraft airframes, engines and other aircraft components to the lessor in a certain condition or pay an amount to the lessor based on the airframe and engine's actual return condition. Lease return costs include all costs that would be incurred at the return of the aircraft, including costs incurred to repair the airframe and engines to the required condition as stipulated by the lease. Lease return costs are recognized beginning when it is probable that such costs will be incurred and they can be estimated.
When determining the probability to accrue lease return costs, there are various estimated costs and factors which need to be considered such as the contractual terms of the lease agreement, current condition of the aircraft, the age of the aircraft at lease expiration, projected number of hours run on the engine at the time of return, and the number of projected cycles run on the airframe at the time of return, among others. Management assesses the need to accrue lease return costs periodically throughout the year or whenever facts and circumstances warrant an assessment. Lease return costs will generally be estimable closer to the end of the lease term but may be estimable earlier in the lease term depending on the contractual terms of the lease agreement and the timing of maintenance events for a particular aircraft.
Aircraft Fuel
Aircraft fuel expense includes jet fuel and associated into-plane costs, taxes, and oil, and realized and unrealized gains and losses associated with fuel derivative contracts, if any.
Advertising
The Company expenses advertising and the production costs of advertising as incurred. Marketing and advertising expenses of $26.8 million, $9.0 million and $9.2 million for the years ended 2024, 2023 and 2022, respectively, were recorded within distribution expense in the consolidated statements of operations.
Income Taxes
The Company accounts for income taxes using the asset and liability method. The Company records a valuation allowance to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that some portion or all of the deferred tax assets will be not realized. As of December 31, 2024 and 2023, the Company had a valuation allowance of $226.4 million and $17.7 million, respectively, recorded within deferred income taxes on the Company's consolidated balance sheets. For additional information, refer to Note 16, Income Taxes.
Stock-Based Compensation
The Company recognizes cost of employee services received in exchange for awards of equity instruments based on the fair value of each instrument at the date of grant. For the majority of awards, compensation expense is recognized on a straight-line basis over the period during which an employee is required to provide service in exchange for an award. Certain awards have performance conditions that must be achieved prior to vesting and are expensed based on the expected achievement at each reporting period. The Company has issued restricted stock awards, performance share award and performance and market share awards. Restricted stock awards are valued at the fair value of the shares on the date of grant. The fair value of performance share awards based on a market condition are estimated through the use of a Monte Carlo simulation model. The fair value of performance share awards based on a performance condition is based on the fair value of the shares on the date of grant. The performance share awards based on a performance condition are evaluated at each report date and adjustments are made to stock-based compensation expense based on the number of shares deemed probable of issuance upon vesting. The fair value of the market and performance share awards are estimated through the use of a Monte Carlo simulation model and adjusted based on the number of shares deemed probable of issuance upon vesting. For additional information, refer to Note 11, Stock-Based Compensation.
Pratt & Whitney AOG Credits
On July 25, 2023, RTX Corporation, parent company of Pratt & Whitney, announced that it had determined that a rare condition in the powdered metal used to manufacture certain engine parts will require accelerated inspection of the PW 1100G-JM geared turbo fan (“GTF”) fleet, which powers the Company's A320neo family of aircraft.

On March 26, 2024, the Company entered into an agreement (the “Agreement”) with International Aero Engines, LLC ("IAE"), an affiliate of Pratt & Whitney, pursuant to which IAE provided the Company with a monthly credit, subject to certain conditions, as compensation for each of the Company's aircraft unavailable for operational service due to GTF engine issues from October 1, 2023 through the end of 2024.

The credits were accounted for as vendor consideration in accordance with ASC 705-20 and were recognized as a reduction of the purchase price of the goods or services acquired from IAE during the period, which may include the purchase of maintenance, spare engines and short-term rentals of spare engines, based on an allocation that corresponds to the Company’s progress towards earning the credits. Pratt & Whitney agreed to issue the Company $150.6 million in credits related to the aircraft on ground ("AOG") days through December 31, 2024, of which the entire amount was recognized in 2024. As of December 31, 2024, the Company had recorded $122.2 million of credits as a reduction in the cost basis of assets purchased from IAE within flight equipment and deferred heavy maintenance, net on the Company's consolidated balance sheets. During the twelve months ended December 31, 2024, the Company recorded $28.4 million of these credits on the Company's consolidated statements of operations within maintenance, materials and repairs and aircraft rent. In addition, during the twelve months ended December 31, 2024, the Company recognized lower depreciation expense of $11.4 million related to credits recognized as a reduction of the cost basis of assets purchased from IAE in depreciation and amortization within the Company's consolidated statements of operations.

The temporary removal of engines from service is expected to continue through at least 2026. The Company is currently discussing arrangements with Pratt & Whitney for any of its aircraft that remain unavailable for operational service after December 31, 2024.
Concentrations of Risk
Aircraft Fuel. The Company’s business may be adversely affected by increases in the price of aircraft fuel, the volatility of the price of aircraft fuel, or both. Aircraft fuel, one of the Company’s largest expenditures, represented approximately 25%, 31% and 34% of total operating expenses in 2024, 2023 and 2022, respectively.
The Company’s operations are largely concentrated in the southeast United States with Fort Lauderdale being the highest volume fueling point in the system. Gulf Coast Jet indexed fuel is the basis for a substantial majority of the Company’s fuel consumption. Any disruption to the oil production or refinery capacity in the Gulf Coast, as a result of weather or any other disaster, or disruptions in supply of jet fuel, dramatic escalations in the costs of jet fuel and/or the failure of fuel providers to perform under fuel arrangements for other reasons could have a material adverse effect on the Company’s financial condition and results of operations.
Weather Conditions. The Company’s operations will continue to be vulnerable to weather conditions (including hurricane season or snow and severe winter weather), which could disrupt service or create air traffic control problems. These events may result in decreased revenue and/or increased costs.
Limited number of vendors. The Company relies on a limited number of vendors for the delivery of additional aircraft and engines - currently Airbus A320-family, single-aisle aircraft, powered by engines manufactured by IAE and Pratt & Whitney. Due to the relatively small size of the Company's fleet and high utilization rate, the unavailability of aircraft and engines, as well as the reduced capacity, resulting from delivery delays or performance issues from these vendors, could have a material adverse effect on the Company’s business, results of operations and financial condition.
Employees. As of December 31, 2024, the Company had six union-represented employee groups that together represented approximately 84% of all employees. A strike or other significant labor dispute with the Company’s unionized employees is likely to adversely affect the Company’s ability to conduct business. Additional disclosures are included in Note 17, Commitments and Contingencies.
v3.25.0.1
Recent Accounting Developments
 12 Months Ended
Dec. 31, 2024
Accounting Standards Update and Change in Accounting Principle [Abstract]  
Recent Accounting Developments Recent Accounting Developments
Recently Adopted Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This standard improves reportable segment disclosure requirements by expanding annual and interim disclosure requirements for reportable segments, providing new segment disclosure requirements for entities with a single reportable segment, and adding other disclosure requirements. This standard is effective for the Company for fiscal years beginning January 1, 2024 and for interim periods beginning January 1, 2025. The Company adopted this standard effective January 1, 2024 with no impact to its consolidated financial statements. Refer to Note 19, Operating Segments and Related Disclosures for additional information.

Recently Issued Accounting Pronouncements Not Yet Adopted

In December 2023, the FASB issued ASU No. 2023-09 (“ASU 2023-09”), Income Taxes (Topic 740): Improvement to Income Tax Disclosures to enhance the transparency and decision usefulness of income tax disclosures. This standard is effective for the Company for fiscal years, and interim periods within those years, beginning January 1, 2025 on a prospective basis. Early adoption is permitted. The Company is currently evaluating the impact of this new standard.
In November 2024, the FASB issued ASU No. 2024-03 (“ASU 2024-03”), Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40). This standard requires disclosure of specific information about costs and expenses. This standard is effective for the Company for fiscal years, and interim periods within those years, beginning January 1, 2027 on a prospective basis. Early adoption is permitted. The Company is currently evaluating the impact of this new standard.
v3.25.0.1
Chapter 11 Proceedings
 12 Months Ended
Dec. 31, 2024
Reorganizations [Abstract]  
Chapter 11 Proceedings Chapter 11 Proceedings
Voluntary Filing under Chapter 11

On November 18, 2024 (the “Petition Date”), the Company commenced a voluntary case (the “Chapter 11 Case”) under Chapter 11 of Title 11 of the United States Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Southern District of New York (the “Bankruptcy Court”), and, on November 25, 2024, Spirit's subsidiaries (together with Spirit, the “Company Parties”) also filed voluntary petitions seeking relief under Chapter 11 of the Bankruptcy Code and joined the Chapter 11 Case (collectively, the “Chapter 11 Cases”). Since the Petition Date, the Company has been operating its businesses as a debtor-in-possession under the jurisdiction of the Bankruptcy Court in accordance with the applicable provisions of the Bankruptcy Code and orders of the Bankruptcy Court. Spirit received approval from the Bankruptcy Court for a variety of “first day” motions to continue their ordinary course operations during the Chapter 11 Case. On February 20, 2025, the Bankruptcy Court entered the Confirmation Order confirming the Plan.

Commencing the Chapter 11 Cases constituted an event of default that accelerated the Company Parties’ respective obligations under the revolving credit facility, the convertible notes due 2025, the convertible notes due 2026, the 8.00% senior secured notes, the fixed-rate term loans and enhanced equipment trust certificates (collectively, the “Debt Instruments”). The Debt Instruments provide that, as a result of the Chapter 11 Cases, the principal and interest due thereunder shall be immediately due and payable. Any efforts to enforce such payment obligations under the Debt Instruments were automatically
stayed as a result of the Chapter 11 Cases, and the stakeholders’ rights of enforcement in respect of the Debt Instruments were subject to the applicable provisions of the Bankruptcy Code.

Restructuring Support Agreement

On November 18, 2024, Spirit entered into a Restructuring Support Agreement (the “Restructuring Support Agreement” and the holders parties thereto, the “Supporting Stakeholders”), with certain holders of its 8.00% senior secured notes (the “Senior Secured Notes,” and the holders, the “Senior Secured Noteholders”) and certain holders of the convertible notes (the “Convertible Noteholders”). The Restructuring Support Agreement contemplates agreed-upon terms for a comprehensive restructuring with respect to the Company Parties’ capital structure (the “Restructuring”) to be implemented through a proposed pre-arranged plan of reorganization (the “Plan”).

Pursuant to the Restructuring Support Agreement and the Plan, the Supporting Stakeholders agreed, subject to certain terms and conditions, to the equitization of $410.0 million of outstanding Senior Secured Notes and $385.0 million of outstanding convertible notes, as well as a backstopped $350.0 million new money equity raise upon emergence from the Chapter 11 Cases.

The material terms of the Restructuring are set forth in the term sheets attached to the Restructuring Support Agreement, which terms include, among other things:

•Vendors, aircraft lessors and holders of secured aircraft indebtedness will continue to be paid in the ordinary course and will not be impaired.
•The Supporting Stakeholders committed to provide a $300.0 million new money senior secured super-priority DIP Facility (as defined below), as further described under “Debtor-in-Possession Financing.” The DIP Facility is expected to be repaid in full in cash on the effective date of the Plan (the “Effective Date”).
•On the Effective Date, the Company (as reorganized, “Reorganized Spirit”) will issue a single class of common equity interests (the “New Common Equity”) and warrants to purchase New Common Equity (the “New Warrants”) to certain of its creditors as follows: (a) 76.0% pro rata to the Senior Secured Noteholders and (b) 24.0% pro rata to the Convertible Noteholders, subject to dilution on account of the Management Incentive Plan (as defined in the Plan), the $350.0 million Equity Rights Offering (as defined below), as further described under “Backstop Commitment Agreement,” and certain adjustments set forth in the Plan.
•On the Effective Date, Reorganized Spirit issued $840.0 million of senior secured notes due 2030 (the “Exit Secured Notes”), at an interest rate of (x) 12.00% per annum, of which 8.00% per annum shall be payable in cash and 4.00% per annum shall be payable in-kind or (y) at 11.00% per annum payable in cash, to certain of its creditors as follows: (a) $700.0 million in the aggregate, pro rata, to the Senior Secured Noteholders and (b) $140.0 million in the aggregate, pro rata, to the Convertible Noteholders, subject to certain adjustments set forth in the Plan.
•All of the Company’s existing common stock and other equity interests will be cancelled without any distributions to the holders of such common stock and other equity interests on account thereof.

Backstop Commitment Agreement

On November 18, 2024, Spirit entered into a Backstop Commitment Agreement (the “Backstop Commitment Agreement”), with the backstop parties named therein (the “Backstop Commitment Parties”). The terms of the Backstop Commitment Agreement are, in pertinent part, as follows:

•Pursuant to the Backstop Commitment Agreement, the Backstop Commitment Parties agreed to backstop an equity rights offering of New Common Equity (the “Equity Rights Offering”) for an aggregate purchase price of $350.0 million at 70.0% of Plan Equity Value (as defined in the Backstop Agreement) (such New Common Equity, the “Offering Shares”), as contemplated by the Restructuring Support Agreement.
•Subject to adjustments described below, the Backstop Commitment Agreement provides that $175.0 million of the Offering Shares will be raised by soliciting commitments from certain of the Company’s creditors as follows: (a) $137.81 million from Senior Secured Noteholders (the “Senior Secured Notes Subscription Rights”) and (b) $37.19 million from Convertible Noteholders (the “Convertible Notes Subscription Rights”).
•Subject to adjustments described below, the Backstop Commitment Agreement provides that $175.0 million of the Offering Shares will be reserved for purchase by the Backstop Commitment Parties as follows: $137.81 million by the Senior Secured Backstop Commitment Parties (as defined in the Backstop Commitment Agreement) (the “Senior Secured Direct Allocation”) and $37.19 million by the Convertible Backstop Commitment Parties (as defined in the Backstop Commitment Agreement) (the “Convertible Direct Allocation” and, together with the Senior Secured Direct Allocation, the “Direct Allocation”).
•Because Senior Secured Noteholders holding, in the aggregate, at least 90.0% of the aggregate principal amount of the Senior Secured Notes claims had executed the Restructuring Support Agreement by 11:59 p.m., New York City time, on November 25, 2024, the amount of the Senior Secured Notes Subscription Rights increased to $248.06 million and the Senior Secured Direct Allocation was reduced to $27.56 million.
•Because Convertible Noteholders holding, in the aggregate, at least 90.0% of the aggregate principal amount of the convertible notes claims had executed the Restructuring Support Agreement by 11:59 p.m., New York City time, on November 25, 2024, the amount of the Convertible Notes Subscription Rights increased to $66.94 million and the Convertible Direct Allocation was reduced to $7.44 million.
•As consideration for the commitment by the Backstop Commitment Parties, and subject to approval by the Bankruptcy Court: (i) a “Backstop Premium” will be paid to the Backstop Commitment Parties by the Company in an aggregate number of shares of New Common Equity equal to 10.0% of the total number of shares of New Common Equity issued by the Company upon emergence from bankruptcy as distributions under the Plan. If the Backstop Commitment Agreement is terminated under certain circumstances as set forth therein, the Backstop Commitment Agreement provides for a cash payment of $35.0 million to the Backstop Commitment Parties. Since the Backstop Premium is fully earned as of November 18, 2024, the date the Backstop Commitment Agreement was executed, and is a non-refundable, non-avoidable premium, the Company recorded the entire commitment as of December 31, 2024. This amount was recorded within reorganization expense in the Company's consolidated statement of operations and within other current liabilities on its consolidated balance sheet.

The transactions contemplated by the Backstop Commitment Agreement are conditioned upon the satisfaction or waiver of customary conditions for transactions of this nature, including, among other things, (i) the confirmation of the Plan by the Bankruptcy Court, (ii) the occurrence of the Effective Date and (iii) the Restructuring Support Agreement remaining in full force and effect.

Debtor-in-Possession Financing

Prior to the Petition Date, Spirit and certain lenders and note purchasers (collectively, the “DIP Lenders”) agreed to enter into an approximately $300.0 million senior secured super-priority debtor‑in‑possession facility (the “DIP Facility”) consisting of new money term loans and new money notes, which will bear interest at a rate per annum equal to (a) term SOFR plus 7.00% per annum or (b) an alternate base rate plus 6.00% per annum.

The DIP Facility contains various representations and warranties, affirmative and negative covenants and events of default customary for debtor-in-possession financings of this type, including covenants mandating compliance by the Company with a 13-week budget, variance testing and other reporting requirements.

Spirit’s obligations under the proposed DIP Facility will be guaranteed by each subsidiary of Spirit. In addition, upon entry and subject to the terms of the order approving the DIP Facility, the claims of the DIP Lenders will be (i) entitled to super-priority administrative expense claim status, subject to certain customary exclusions in the credit documentation and (ii) secured by perfected senior security interests and liens on certain property of the Company, subject to certain exclusions and exceptions carve-out.

The proceeds of all or a portion of the DIP Facility may be used for, among other things, (i) prepetition obligations, (ii) adequate protection payments, (iii) the fees, costs, and expenses of administering the Chapter 11 Cases and (iv) working capital and other general corporate needs of Spirit in the ordinary course of business.

On December 23, 2024, in connection with the Chapter 11 Cases, the Company entered into a Superpriority Secured Debtor In Possession Term Loan Credit and Note Purchase Agreement, (the “DIP Credit Agreement”), with Wilmington Savings Fund Society, FSB, as administrative agent and collateral agent (the “Agent”) and the creditors from time to time party thereto (collectively, the “DIP Creditors”). Refer to Note 13, Debt and Other Obligations for additional information.

Equity Rights Offering

On December 30, 2024, the Company launched an equity rights offering (the “Equity Rights Offering”) of equity securities of the reorganized Company in an aggregate amount of $350.0 million at a purchase price of $14.00 per share. The final expiration date for the Equity Rights Offering occurred on February 20, 2025. The Company expects to close the Equity Rights Offering on the Effective Date. Pursuant to the terms of the Backstop Commitment Agreement, the Backstop Commitment Parties would receive a backstop fee in the amount of $35.0 million (payable in shares of reorganized Spirit common stock valued at $14.00 per share).
Exit Revolving Credit Facility

The Company has secured a commitment from certain of its prepetition debtholders (collectively, the “Exit RCF Lenders”) pursuant to that certain Commitment Letter, dated as of January 14, 2025 (the “Exit RCF Commitment Letter”), to provide up to $300.0 million in financing in the form of a senior secured revolving credit facility (the “Exit Revolving Credit Facility”). The Company will enter into the Exit Revolving Credit Facility concurrently with emergence from the Chapter 11 Cases. The Exit Revolving Credit Facility is comprised of (i) commitments by the Exit RCF Lenders to provide revolving credit loans and letters of credit in an aggregate amount equal to $275.0 million (the “Exit RCF Commitments”) and (ii) an uncommitted incremental revolving credit facility in an aggregate amount up to $25.0 million. The Company’s uses of the proceeds of the Exit Revolving Credit Facility shall include, among other items, working capital and other general corporate needs of the Company and its subsidiaries.

The Company’s obligations under the Exit Revolving Credit Facility will be guaranteed by each subsidiary of the Company (the “Guarantors”). In addition, the obligations under the Exit Revolving Credit Facility will be secured by perfected senior security interests and liens on certain property of the Company and the Guarantors, subject to certain exclusions, exceptions and carve-outs.

Subject to certain exceptions and conditions, the Company will be obligated to prepay or offer to prepay, as the case may be, all or a portion of the obligations under the Exit Revolving Credit Facility with the net cash proceeds of certain asset sales, with cash from its balance sheet in order to remain in compliance with a collateral coverage ratio and concentration limits, in connection with a change of control and in connection with certain mergers with other airlines. The Exit Revolving Credit Facility will bear interest at a variable rate equal to the Company’s choice of (a) adjusted term SOFR plus 3.25% per annum or (b) alternate base rate plus 2.25% per annum.

Automatic Stay and Other Protections

Subject to certain exceptions under the Bankruptcy Code, pursuant to Section 362 of the Bankruptcy Code, the filing of Spirit’s Chapter 11 Case automatically stayed the continuation of most legal proceedings or the filing of other actions against or on behalf of Spirit or its property to recover on, collect or secure a claim arising prior to the Petition Date or to exercise control over property of Spirit’s bankruptcy estate, unless and until the Bankruptcy Court modifies or lifts the automatic stay as to any such claim. Notwithstanding the general application of the automatic stay described above and other protections afforded by the Bankruptcy Code, governmental authorities may determine to continue actions brought under their police and regulatory powers.

NYSE Delisting

On November 18, 2024, the Company received written notice (the “Delisting Notice”) from the New York Stock Exchange
(the “NYSE”) notifying the Company that, as a result of the Chapter 11 Case and in accordance with NYSE Listed Company Manual Section 802.01D, the NYSE had determined that the Company’s shares of common stock would be delisted from the NYSE and that trading of the Company’s shares of common stock on NYSE was suspended immediately. As a result of the suspension and expected delisting, the Company’s shares of common stock commenced trading on the OTC Pink Market under the symbol “SAVEQ” on November 19, 2024. On December 5, 2024, NYSE filed a Form 25 for the Company in connection with the delisting of its shares of common stock from the NYSE. The delisting became effective ten days after the Form 25 was filed. In accordance with Rule 12d2-2 of the Exchange Act, the deregistration of its shares of common stock under Section 12(b) of the Exchange Act will become effective 90 days after the date of the Form 25 filing.

Liabilities Subject to Compromise

The Company's 8.00% senior secured notes, convertible notes due 2025 and convertible notes due 2026, as of the Petition Date, have been classified as “Liabilities Subject to Compromise” on the Company's consolidated balance sheets. These liabilities are reported at the amounts expected to be allowed as claims by the Bankruptcy Court, although they may be settled for less. At December 31, 2024, “liabilities subject to compromise” of $1.6 billion consisted of the notes listed below as of the Petition Date:
December 31, 2024
(in millions)
8.00% senior secured notes due in 2025
$1,110.0 
Convertible notes due in 2025$25.1 
Convertible notes due in 2026500.0 
Liabilities subject to compromise$1,635.1 


Prepetition Charges

Expenses incurred prior to November 18, 2024 in relation to the Cases are recorded within special charges, non-operating on the Company's consolidated statements of operations. As of December 31, 2024, the Company recorded $15.5 million of prepetition charges primarily related to professional and other fees.

Reorganization Items

Any expenses and losses incurred or realized as of or subsequent to the Petition Date and as a direct result of the Cases are recorded within reorganization expense on the Company's consolidated statements of operations. For the twelve months ended December 31, 2024, the Company recorded $96.8 million of reorganization expense which consisted of the following items:

December 31, 2024
(in millions)
Backstop premium(1)
$35.0 
Unamortized debt discounts (2)
20.7
Unamortized debt issuance costs (2)
9.0
DIP term loan financing fees12.6
Legal, consulting and other fees19.5
Total reorganization expense$96.8 

(1)    Refer to “Backstop Commitment Agreement” section above for additional information.
(2) Includes the unamortized discount as of the Petition Date related to the Company's 8.00% senior secured notes and convertible notes due 2025, as well as the unamortized debt issuance costs as of the Petition Date related to the Company's 8.00% senior secured notes, convertible notes due 2025 and convertible notes due 2026.
v3.25.0.1
Special Charges and Credits
 12 Months Ended
Dec. 31, 2024
Special Charges and Credits [Abstract]  
Special Charges and Credits Special Charges and Credits
During the twelve months ended December 31, 2024, the Company recorded $28.1 million in net charges within special charges (credits) on the Company's consolidated statements of operations, in legal, advisory and other fees related to the former Merger Agreement with JetBlue entered into on July 28, 2022 and terminated on March 1, 2024. In addition, as part of the Merger Agreement with JetBlue, the Company implemented an employee retention award program (the "JetBlue Retention Award Program") during the third quarter of 2022. The first installment was paid in July 2023 and the second installment was paid in March 2024 upon termination of the former JetBlue Merger Agreement. During the twelve months ended December 31, 2024, the Company recorded $8.0 million within special charges (credits) on the Company's consolidated statements of operations, related to the JetBlue Retention Award Program.

During the twelve months ended December 31, 2023, the Company recorded $50.0 million within special charges (credits) on the Company's consolidated statements of operations in legal, advisory and other fees related to the former Merger Agreement with JetBlue entered into on July 28, 2022 and terminated on March 1, 2024. During the twelve months ended December 31, 2023, the Company recorded $19.5 million within special charges (credits) on the Company's consolidated statements of operations, related to the JetBlue Retention Award Program.
During the twelve months ended December 31, 2022, the Company recorded $333.7 million within special charges (credits) on the Company's consolidated statements of operations in impairment charges related to the planned acceleration of the retirement of 29 of its A319 aircraft.

In addition, during the twelve months ended December 31, 2022, the Company recorded $47.2 million within special charges (credits) on the Company's consolidated statements of operations, in legal, advisory and other fees related to the former merger agreement with Frontier Airlines (the "Former Frontier Merger Agreement"), JetBlue's unsolicited proposal, received in March 2022, to acquire all of the Company's outstanding shares in an all-cash transaction and the JetBlue Merger Agreement entered into on July 28, 2022 and terminated on March 1, 2024.

As part of the Former Frontier Merger Agreement, the Company implemented an employee retention award program (the "Frontier Retention Award Program"). On July 27, 2022, the Frontier Merger Agreement was mutually terminated; therefore, 50% of the target retention award was awarded to the Company's employees during the third quarter of 2022. In addition, as part of the JetBlue Merger Agreement, the Company implemented the JetBlue Retention Award Program during the third quarter of 2022. During the twelve months ended December 31, 2022, the Company recorded $39.3 million within special charges (credits) on the Company's consolidated statements of operations, related to the Company's retention award programs.

    Special Charges, Non-Operating

During the twelve months ended December 31, 2024, the Company recorded $15.5 million in special charges, non-operating within other (income) expense in the consolidated statement of operations in legal, advisory and other fees related to the Company's voluntary bankruptcy filing, incurred prior to the petition filing date of November 18, 2024. Refer to Note 3, Chapter 11 Proceedings for additional information on the Company's bankruptcy proceedings.

During the twelve months ended December 31, 2023 and December 31, 2022, the Company had no special charges, non-operating within other (income) expense in the consolidated statements of operations.
v3.25.0.1
Loss (Gain) on Disposal of Assets
 12 Months Ended
Dec. 31, 2024
Discontinued Operations and Disposal Groups [Abstract]  
Loss (Gain) on Disposal of Assets Loss (Gain) on Disposal of Assets
During the twelve months ended December 31, 2024, the Company recorded a loss of $273.9 million in loss (gain) on disposal of assets in the consolidated statement of operations.
Loss (gain) on disposal of assets for the twelve months ended December 31, 2024 included $282.5 million in impairment charges recorded during the fourth quarter 2024. These charges are associated with the Company's plan to early retire and sell 23 A320ceo and A321ceo aircraft, in accordance with the aircraft sale and purchase agreement with GAT entered into on October 29, 2024. For additional information, refer to Note 1, Summary of Significant Accounting Policies.
During the first quarter of 2024, the Company completed five sale leaseback transactions (on aircraft previously owned by the Company) of which two resulted in operating leases and three would have been deemed finance leases resulting in failed sale leaseback transactions. As a result of the two sale leaseback transactions that resulted in operating leases, the Company recorded a related loss of $1.7 million within loss (gain) on disposal of assets during the twelve months ended December 31, 2024. Refer to Note 14, Leases for additional information on the five sale leaseback transactions.
In addition, loss (gain) on disposal of assets for the twelve months ended December 31, 2024, included a $25.1 million gain recorded as a result of eight aircraft sale leaseback transactions related to new aircraft deliveries completed during 2024, a $0.4 million loss recorded as a result of the sale of two aircraft to GAT, an $11.9 million loss recorded as a result of the sale of 17 A319 airframes and 38 A319 engines during 2024, and $2.5 million in losses during the twelve months ended December 31, 2024, related to the write-off of obsolete assets and other adjustments.
During twelve months December 31, 2023, the Company recorded a loss of $34.0 million in loss (gain) on disposal of assets in the consolidated statement of operations.
During December 2023, the Company completed 20 sale leaseback transactions (on aircraft previously owned by the Company) of which, 6 resulted in operating leases and 14 would have been deemed finance leases resulting in failed sale leaseback transactions. As a result of the 6 sale leaseback transactions that resulted in operating leases, the Company recorded a related loss of $32.1 million within loss (gain) on disposal of assets. Loss (gain) on disposal of assets for the twelve months ended December 31, 2023 also included a $3.0 million net gain recorded as a result of 10 aircraft sale leaseback transactions related to new aircraft deliveries completed during the twelve months ended December 31, 2023.

During the twelve months ended December 31, 2023, the Company completed the sale of 12 A319 airframes and 20 A319 engines and recorded a related net loss of $1.6 million. In addition, the Company recorded a $3.3 million loss primarily related to the disposal of obsolete assets.

During the twelve months ended December 31, 2022, the Company recorded $46.6 million in loss (gain) on disposal of assets in the consolidated statement of operations. This loss on disposal of assets mainly consisted of $38.5 million related to the loss on 16 aircraft sale leaseback transactions completed during 2022 and $6.6 million related to the impairment of 1 spare engine during the first quarter of 2022 which was damaged beyond economic repair.
v3.25.0.1
Letters of Credit
 12 Months Ended
Dec. 31, 2024
Financial Instruments Pledged as Collateral [Abstract]  
Letters of Credit Letters of Credit
As of December 31, 2024, the Company had $68.0 million in standby letters of credit collateralized by $68.0 million of restricted cash, of which $58.8 million were issued letters of credit. As of December 31, 2023, the Company had a $85.0 million standby letters of credit secured by $75.0 million restricted cash, of which $55.9 million were issued letters of credit.
v3.25.0.1
Credit Card Processing Arrangements
 12 Months Ended
Dec. 31, 2024
Credit Card Processing Arrangements [Abstract]  
Credit Card Processing Arrangements Credit Card Processing Arrangements
The Company has agreements with organizations that process credit card transactions arising from the purchase of air travel, baggage charges and other ancillary services by customers. As it is standard in the airline industry, the Company's contractual arrangements with credit card processors permit them, under certain circumstances, to retain a holdback or other collateral, when future air travel and other future services are purchased via credit card transactions. The required holdback is the amount of the Company's overall credit card sales that its credit card processors hold to cover refunds to customers if the Company fails to fulfill its flight obligations.
The Company's credit card processors do not require the Company to maintain cash collateral provided that the Company satisfies certain liquidity and other financial covenants. Failure to meet these covenants would provide the processors the right to place a holdback, resulting in a commensurate reduction of unrestricted cash. The maximum potential exposure to cash holdbacks by the Company's credit card processors, based upon advance ticket sales and Spirit Saver$ Club® memberships as of December 31, 2024 and 2023, was $469.2 million and $408.3 million, respectively.
On July 2, 2024, the Company entered into a letter agreement with its primary credit card processor that modified its existing agreement to, among other things, extend the term until December 31, 2025, including automatic extensions for two successive one-year terms (subject to the right of either party to opt out of any extension term by written notice to the other within a specified period of time prior to the commencement of any extension term); provided that if the Company’s senior secured notes due 2025 are not extended or refinanced by September 20, 2024 (the “2025 Notes Extension Deadline”), in a specified minimum outstanding principal amount thereof, then the term will revert to December 31, 2024 (the “Early Maturity Date”). Based on the terms of the agreement, in July 2024, the Company deposited $200.0 million into a deposit account and deposited $50.0 million into a restricted account. The $200.0 million deposited into the deposit account is considered a compensating balance arrangement that does not legally restrict the Company's use of this cash. As such, the balance of the deposit account is included in cash and cash equivalents within the Company's consolidated balance sheets, and the $50.0 million in the restricted account is included in restricted cash within the Company's consolidated balance sheets going forward.
On September 9, 2024, the Company entered into a letter agreement which modified its existing credit card processing agreement to extend the 2025 Notes Extension Deadline from September 20, 2024 to October 21, 2024.

On October 11, 2024, the Company entered into a letter agreement (the “Credit Card Processing Amendment”) which modified its existing credit card processing agreement to extend (i) the 2025 Notes Extension Deadline from October 21, 2024 to December 23, 2024 and (ii) the Early Maturity Date from December 31, 2024 to March 3, 2025.

Pursuant to the Credit Card Processing Amendment, the filing of the Chapter 11 Cases on November 18, 2024 constitutes a breach of contract, subject to the automatic stay resulting from the Chapter 11 Cases. However, as of December 31, 2024 and 2023, the Company was in compliance with other liquidity and other financial covenants in its credit card processing agreement. For additional information on the Company's bankruptcy proceedings and its related automatic stay and other protections, refer to Note 3, Chapter 11 Proceedings.
Additionally, the Company provided a $20.7 million deposit to a credit card processor recorded within deposits and other current assets in its consolidated balance sheets.
v3.25.0.1
Short-term Investment Securities
 12 Months Ended
Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]  
Short-term Investment Securities Short-term Investment Securities
The Company's short-term investment securities are classified as available-for-sale and generally consist of U.S. Treasury and U.S. government agency securities with contractual maturities of twelve months or less. These securities are stated at fair value within current assets on the Company's consolidated balance sheet. Realized gains and losses on sales of investments, if any, are reflected in non-operating other (income) expense in the consolidated statements of operations. Unrealized gains and losses on investment securities are reflected as a component of accumulated other comprehensive income, ("AOCI").

As of December 31, 2024 and December 31, 2023, the Company had $118.3 million and $112.5 million, respectively, in short-term available-for-sale investment securities. During the twelve months ended December 31, 2024, 2023 and 2022, these investments earned interest income at a weighted-average fixed rate of approximately 4.9%, 4.5% and 1.0%, respectively. For the twelve months ended December 31, 2024 and December 31, 2023, an unrealized gain of $169 thousand and $298 thousand, net of deferred taxes, respectively, were recorded within AOCI related to these investment securities. For the twelve months ended December 31, 2024 and December 31, 2023, the Company did not recognize any realized gains or losses related to these securities, as the Company did not transact any sales of these securities during this period. As of December 31, 2024 and December 31, 2023, $201 thousand and $32 thousand, net of tax, respectively, remained in AOCI, related to these instruments.
v3.25.0.1
Other Current Liabilities
 12 Months Ended
Dec. 31, 2024
Payables and Accruals [Abstract]  
Other Current Liabilities Other Current Liabilities
Accrued liabilities included in other current liabilities as of December 31, 2024 and 2023 consist of the following:

 As of December 31,
20242023
(in thousands)
Salaries, wages and benefits$187,626 $187,723 
Federal excise and other passenger taxes and fees payable110,141 104,447 
Aircraft maintenance103,133 58,800 
Airport obligations66,518 125,278 
Backstop premium obligation35,000 — 
Interest payable26,780 24,732 
Aircraft and facility lease obligations23,926 36,115 
Fuel5,202 64,149 
Other47,513 104,054 
Other current liabilities$605,839 $705,298 
v3.25.0.1
Equity
 12 Months Ended
Dec. 31, 2024
Equity [Abstract]  
Equity Equity
The Company’s amended and restated certificate of incorporation dated June 1, 2011, authorizes the Company to issue up to 240,000,000 shares of common stock, $0.0001 par value per share, 50,000,000 shares of non-voting common stock, $0.0001 par value per share and 10,000,000 shares of preferred stock, $0.0001 par value per share. All of the Company’s issued and outstanding shares of common stock and preferred stock, if any, are duly authorized, validly issued, fully paid and non-assessable. The Company’s shares of common stock and non-voting common stock are not redeemable and do not have preemptive rights. As of December 31, 2024 and 2023, there were no shares of preferred stock or non-voting common stock outstanding.
Common Stock
Dividend Rights. Holders of the Company’s common stock are entitled to receive dividends, if any, as may be declared from time to time by the Company’s board of directors (the “Board”) out of legally available funds ratably with shares of the Company’s non-voting common stock, subject to preferences that may be applicable to any then outstanding preferred stock and limitations under Delaware law.
Voting Rights. Each holder of the Company’s common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. The Company’s stockholders do not have cumulative voting rights in the election of directors. Accordingly, holders of a majority of the voting shares are able to elect all of the directors properly up for election at any given stockholders’ meeting.
Liquidation. In the event of the Company’s liquidation, dissolution or winding up, holders of the Company's common stock will be entitled to share ratably with shares of the Company’s non-voting common stock in the net assets legally available for distribution to stockholders after the payment of all of the Company’s debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then outstanding shares of preferred stock.

Rights and Preferences. Holders of the Company’s common stock have no preemptive, conversion, subscription or other rights and there are no redemption or sinking fund provisions applicable to the Company’s common stock. The rights, preferences and privileges of the holders of the Company’s common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of the Company’s preferred stock that the Company may designate in the future.

Treasury Stock

Treasury stock is comprised of repurchases made from employees who received restricted stock awards or performance share awards. During the year ended December 31, 2024, 2023 and 2022, the Company repurchased 96 thousand, 142 thousand and 107 thousand shares, respectively, for $0.7 million, $2.6 million and $2.4 million, respectively. During the year ended December 31, 2024, 2023 and 2022, the Company did not retire any treasury shares.
Warrants

In connection with the Company's participation in the PSP1 agreement with the Treasury, during 2020, the Company issued to the Treasury warrants pursuant to a warrant agreement to purchase up to 520,797 shares of the Company's common stock at a strike price of $14.08 per share (the closing price for the shares of the Company's common stock on April 9, 2020). In connection with the Company's participation in the PSP2 and PSP3 agreements with the Treasury, during 2021, the Company issued to the Treasury warrants pursuant to a warrant agreement to purchase up to 137,753 and 80,539 shares of the Company's common stock at a strike price of $24.42 (the closing price for the shares of the Company's common stock on December 24, 2020) and $36.45 (the closing price for the shares of the Company's common stock on March 10, 2021) per share.
The warrants are transferable and have no voting rights. The warrants expire in five years from the date of issuance and at the Company's option, may be settled on a "net cash" or "net shares" basis. The 739,089 warrants issued in connection with the PSP1, PSP2 and PSP3 agreements represent less than 1% of the outstanding shares of the Company's common stock as of December 31, 2024.
The Company concluded that the PSP1, PSP2 and PSP3 warrant agreement are a derivative contract classified within equity, at fair value upon issuance, within the Company’s consolidated balance sheet. Equity-classified contracts are initially measured at fair value and subsequent changes in fair value are not recognized as long as the contract continues to be classified in equity. As of December 31, 2024, the Company had recorded $4.3 million, net of issuance costs, in APIC related to the fair value of the warrants issued.
Due to the payment of the Approval Prepayment and each of the Additional Prepayment Amounts, in accordance with the terms of the respective debt indentures and warrant agreements, the Company announced related adjustments to the exercise prices and warrant shares of the PSP1, PSP2 and PSP3 warrants outstanding. On March 1, 2024, Spirit, JetBlue and Sundown Acquisition Corp., a Delaware corporation and a direct, wholly owned subsidiary of JetBlue, entered into a Termination Agreement (the “Termination Agreement”), pursuant to which the Merger Agreement was terminated, effective immediately. JetBlue ceased paying Additional Prepayment Amounts and, therefore, no further adjustments to the exercise prices and warrant shares of the PSP1, PSP2 and PSP3 warrants outstanding were made in connection with the Merger Agreement. As of December 31, 2024, the exercise prices of the PSP1, PSP2 and PSP3 warrants were $11.393, $19.761 and $29.496, respectively and the number of warrant shares issuable upon the exercise of the PSP1, PSP2 and PSP3 warrants were adjusted to 643,625.20, 170,230.67 and 99,526.95, respectively.
Equity Rights Offering
On December 30, 2024, the Company launched an equity rights offering (the “Equity Rights Offering”) of equity securities of the reorganized Company in an aggregate amount of $350 million. Refer to Note 3, Chapter 11 Proceedings for additional information.
v3.25.0.1
Stock-Based Compensation
 12 Months Ended
Dec. 31, 2024
Share-Based Payment Arrangement [Abstract]  
Stock-Based Compensation Stock-Based Compensation
The Company has stock plans under which directors, officers, key employees and consultants of the Company may be granted restricted stock, stock options, performance share awards and other equity-based instruments as a means of promoting the Company’s long-term growth and profitability. The plans are intended to encourage participants to contribute to, and participate in the success of the Company.
On December 16, 2014, the Board approved the 2015 Incentive Award Plan, or 2015 Plan, which was subsequently approved by the Company's stockholders on June 16, 2015. On March 10, 2021, the Board approved an amendment of the Company's 2015 Incentive Award Plan to increase the number of authorized shares of common stock available for issuance by 3.2 million shares. The amendment was subsequently approved by the Company's stockholders on May 20, 2021.
On June 7, 2024, the Company’s stockholders approved the 2024 Incentive Award Plan (the “2024 Plan”), which was previously adopted by the Board subject to stockholder approval. The 2024 Plan became effective upon stockholder approval and replaces and succeeds the Spirit Airlines, Inc. 2015 Incentive Award Plan.
As of December 31, 2024 and December 31, 2023, 3,691,473 and 3,123,563 shares of the Company’s common stock, respectively, remained available for future issuance under the 2015 Plan, as amended.
Stock-based compensation cost amounted to $7.2 million, $12.0 million and $11.5 million for 2024, 2023 and 2022, respectively. During 2024, 2023 and 2022 there was a $0.3 million, $2.4 million and $2.4 million tax benefit recognized in income related to stock-based compensation.
Restricted Stock and Restricted Stock Units
Restricted stock and restricted stock unit awards are valued at the fair value of the shares on the date of grant. Generally, granted shares and units vest over a two to three year graded vesting period. Each restricted stock unit represents the right to receive one share of common stock upon vesting of such restricted stock unit. Vesting of restricted stock units is based on time-based service conditions. In order to vest, the participant must still be employed by the Company, with certain contractual exclusions, at each vesting event. Generally, within 30 days after vesting, the shares underlying the award will be issued to the participant. In the event a successor corporation in a change in control situation fails to assume or substitute for the restricted stock units, the restricted stock units will automatically vest in full as of immediately prior to the consummation of such change in control. In the event of death or permanent disability of a participant, the restricted stock units will automatically vest in full. Compensation expense is recognized on a straight-line basis over the requisite service period.
A summary of the status of the Company’s restricted stock unit awards (restricted stock awards and restricted stock unit awards) as of December 31, 2024 and changes during the year ended December 31, 2024 is presented below:
Number of SharesWeighted-Average
Grant Date Fair Value ($)
Outstanding at December 31, 2023705,888 20.93 
Granted1,140,060 5.81 
Vested(336,867)20.61 
Forfeited(193,185)12.86 
Outstanding at December 31, 20241,315,896 9.10 
There were 1,140,060 and 500,648 restricted stock shares granted during the years ended December 31, 2024 and December 31, 2023, respectively. As of December 31, 2024 and December 31, 2023, there was $5.8 million and $8.4 million, respectively, of total unrecognized compensation cost related to nonvested restricted stock to be recognized over 1.6 years and 1.8 years, respectively.
The weighted-average fair value of restricted stock granted during the years ended December 31, 2024, 2023 and 2022 was $5.81, $19.58 and $23.48, respectively. The total fair value of restricted stock shares vested during the years ended December 31, 2024, 2023 and 2022 was $2.2 million, $7.2 million and $7.5 million, respectively.
Performance and Market Share Awards
The Company grants certain executives performance and market stock units that vest based on either market, performance or market and performance conditions as part of a long-term incentive plan. The number of shares of common stock underlying each award is determined at the end of the performance period. In order to vest, the executive must still be employed by the Company, with certain contractual exclusions, at the end of the performance period.
Stock-based compensation cost related to these awards amounted to $0.5 million, $3.0 million and $1.5 million for 2024, 2023 and 2022, respectively. As of December 31, 2024 and 2023, there was $3.5 million and $3.9 million, respectively, of total unrecognized compensation cost related to nonvested performance and market share awards expected to be recognized over 1.7 years and 1.8 years, respectively.
v3.25.0.1
Earnings (Loss) per Share
 12 Months Ended
Dec. 31, 2024
Earnings Per Share [Abstract]  
Earnings (Loss) per Share Earnings (Loss) per Share
The following table sets forth the computation of basic and diluted earnings (loss) per common share:

 Year Ended December 31,
202420232022
 (in thousands, except per-share amounts)
Numerator:
Net income (loss)$(1,229,495)$(447,464)$(554,150)
Denominator:
Weighted-average shares outstanding, basic109,495 109,152 108,751 
Effect of dilutive stock awards— — — 
Adjusted weighted-average shares outstanding, diluted109,495 109,152 108,751 
Earnings (loss) per share:
Basic earnings (loss) per common share $(11.23)$(4.10)$(5.10)
Diluted earnings (loss) per common share$(11.23)$(4.10)$(5.10)
    
Anti-dilutive common stock equivalents excluded from the diluted earnings (loss) per share calculations are not material.
v3.25.0.1
Debt and Other Obligations
 12 Months Ended
Dec. 31, 2024
Debt Disclosure [Abstract]  
Debt and Other Obligations Debt and Other Obligations
DIP Credit Agreement and Facility

On December 23, 2024, in connection with the Chapter 11 Cases, the Company entered into a Superpriority Secured Debtor In Possession Term Loan Credit and Note Purchase Agreement, (the “DIP Credit Agreement”), with Wilmington Savings Fund Society, FSB, as administrative agent and collateral agent (the “Agent”) and the creditors from time to time party thereto (collectively, the “DIP Creditors”).

Under the DIP Credit Agreement, the DIP Creditors agreed to provide an aggregate principal amount of $300.0 million (excluding fees of $9.0 million, which were paid in kind in the form of additional principal) in financing in the form of a senior secured debtor-in-possession facility (the “DIP Facility”). The DIP Facility is comprised of (i) new money term loans and (ii) new money notes. The DIP Credit Agreement is secured by substantially all of the Company's assets, subject to certain exclusions, and the Company’s obligations thereunder are guaranteed by each subsidiary of the Company. The claims of the DIP Creditors are entitled to superpriority administrative expense claim status, subject to certain customary exclusions in the credit documentation. The Company’s uses for the DIP Facility include, among other items, (i) prepetition obligations, (ii) adequate protection payments, (iii) the fees, costs, and expenses of administering the Chapter 11 Cases and (iv) working capital and other general corporate needs of Spirit in the ordinary course of business.

The DIP Facility will bear interest at either (i) Term SOFR (as defined in the DIP Credit Agreement) plus 7.00% per annum or (ii) the Base Rate (as defined in the DIP Credit Agreement) plus 6.00% per annum. Interest on the DIP Facility is payable in cash.

The DIP Credit Agreement has a scheduled maturity date of December 23, 2025 (the “Scheduled Maturity Date”). The DIP Credit Agreement will also terminate and all obligations thereunder will become due on the date that is the earliest of the following (i) the Scheduled Maturity Date, (ii) the substantial consummation of a plan of reorganization filed in the Chapter 11 Cases that is confirmed pursuant to an order entered by the Bankruptcy Court, (iii) the acceleration of the obligations under the DIP Credit Agreement and the termination of the unfunded commitments thereunder, (iv) the consummation of a sale of all or substantially all of the assets of the Debtors pursuant to Section 363 of the Bankruptcy Code and (v) dismissal of the Chapter 11 Cases or conversion of any of the Chapter 11 Cases to one or more cases under Chapter 7 of the Bankruptcy Code or appointment of a trustee or examiner in any of the Chapter 11 Cases.

The DIP term loan is recorded within current maturities of long-term debt, net, and finance leases on the Company's consolidated balance sheets as of December 31, 2024. Refer to Note 3, Chapter 11 Proceedings, for additional information.

Exit Revolving Credit Facility

The Company has secured a commitment from the Exit RCF Lenders pursuant to the Exit RCF Commitment Letter, to provide up to $300.0 million in financing in the form of a senior secured revolving credit facility. The Exit Revolving Credit Facility is comprised of (i) commitments by the Exit RCF Lenders to provide revolving credit loans and letters of credit in an aggregate amount equal to $275.0 million and (ii) an uncommitted incremental revolving credit facility in an aggregate amount up to $25.0 million. Refer to Note 3, Chapter 11 Proceedings, for additional information.

Revolving credit facility due in 2026

As of December 31, 2024, the Company borrowed the entire available amount of $300.0 million under the revolving credit facility due in 2026, included within long-term debt, net and finance leases, less current maturities on the Company's consolidated balance sheets. As of December 31, 2023, the Company had $300.0 million undrawn and available under its revolving credit facility due in 2026.

Borrowings under the revolving credit facility will mature on September 30, 2026; provided that if the Company’s senior secured notes due 2025 are not extended or refinanced by June 20, 2025, or the Company’s convertible notes due 2026 are not extended or refinanced by February 12, 2026, in each case in a specified minimum outstanding principal amount thereof, then the maturity will be automatically shortened to June 21, 2025 or February 13, 2026, respectively. The revolving credit facility due in 2026 will be repaid in full in cash on the effective date of the Plan.
The Company may pledge the following types of assets as collateral to secure its obligations under the revolving credit facility: (i) certain take-off and landing rights of the Company at LaGuardia Airport, (ii) certain eligible aircraft spare parts and ground support equipment, (iii) aircraft, spare engines and flight simulators, (iv) real property assets and (v) cash and cash equivalents. The revolving credit facility bears variable interest based on SOFR, plus a 2.00% margin per annum, or another rate, at the Company's election, based on certain market interest rates, plus a 1.00% margin per annum, in each case with a floor of 0%.

The 2026 revolving credit facility requires the Company to maintain (i) so long as any loans or letters of credit are outstanding under the 2026 revolving credit facility, unrestricted cash, cash equivalents, short-term investment securities and unused commitments available under all revolving credit facilities (including the 2026 revolving credit facility) aggregating not less than $450.0 million, of which no more than $300.0 million may be derived from unused commitments under the 2026 revolving credit facility, (ii) a minimum ratio of the borrowing base of the collateral described above (determined as the sum of a specified percentage of the appraised value of each type of such collateral) to outstanding obligations under the 2026 revolving credit facility of not less than 1.0 to 1.0 (if the Company does not meet the minimum collateral coverage ratio, it must either provide additional collateral to secure its obligations under the 2026 revolving credit facility or repay the loans under the 2026 revolving credit facility by an amount necessary to maintain compliance with the collateral coverage ratio), and (iii) the pledged take-off and landing rights of the Company at LaGuardia Airport and a specified number of spare engines in the collateral described above so long as any loans or letters of credit are outstanding under the 2026 revolving credit facility.

Convertible senior notes due 2025

On May 12, 2020, the Company completed the public offering of $175.0 million aggregate principal amount of 4.75% convertible senior notes due 2025 ("convertible notes due 2025").

Noteholders may convert their notes at their option only in the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on June 30, 2020 (and only during such calendar quarter), if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price for each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter; (2) during the five consecutive business days immediately after any five consecutive trading day period (such five consecutive trading day period, the “measurement period”) in which the trading price per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of the Company’s common stock on such trading day and the conversion rate on such trading day; (3) upon the occurrence of certain corporate events or distributions on the Company’s common stock; and (4) at any time from, and including, February 18, 2025 until the close of business on the second scheduled trading day immediately before the maturity date. As of December 31, 2024, the notes did not qualify for conversion by noteholders through February 18, 2025.

As of December 31, 2024, the conversion rate was 97.5929 shares of voting common stock per $1,000 principal amount of convertible notes (equivalent to a conversion price of approximately $10.25 per share of common stock).

The convertible notes due 2025 are recorded within liabilities subject to compromise on the Company's consolidated balance sheets as of December 31, 2024. Refer to Note 3, Chapter 11 Proceedings, for additional information.

Convertible senior notes due 2026

On April 30, 2021, the Company completed the public offering of $500.0 million aggregate principal amount of 1.00% convertible senior notes due 2026 ("convertible notes due 2026").

Noteholders may convert their notes at their option only in the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on June 30, 2021 (and only during such calendar quarter), if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price for each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter; (2) during the five consecutive business days immediately after any five consecutive trading day period (such five consecutive trading day period, the “measurement period”) in which the trading price per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of the Company’s common stock on such trading day and the conversion rate on such trading day; (3) upon the occurrence of certain corporate events or distributions on the Company’s common stock; (4) if the Company calls such notes for redemption; and (5) at any time from, and including, February 17, 2026 until the close of business on the second scheduled trading day immediately before the maturity date. As of December 31, 2024, the notes did not qualify for conversion by noteholders through March 31, 2025.
Based on the terms of the indenture, the Company will have the right to elect to settle conversions in cash, shares of the Company’s common stock or a combination of cash and shares of common stock. Upon conversion of any notes, the Company will pay the conversion value in cash up to at least the principal amount of the notes being converted. The conversion value will be determined over an observation period consisting of 40 trading days. The initial conversion rate was 20.3791 shares of voting common stock per $1,000 principal amount of convertible notes (equivalent to an initial conversion price of approximately $49.07 per share of common stock). The conversion rate will be subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. As of December 31, 2024, the conversion rate was 25.3578 shares of voting common stock per $1,000 principal amount of convertible notes (equivalent to a conversion price of approximately $39.44 per share of common stock).

The Merger Agreement with JetBlue included settlement terms for any conversion of the convertible notes due 2026 to be paid in cash through the closing or termination of the Merger Agreement, causing the conversion option, which is an embedded derivative, not to qualify for the derivative accounting scope exception provided under ASC 815. As such, the Company bifurcated the fair value of the conversion option of the convertible notes due 2026 as a derivative liability with subsequent changes in fair value recorded in earnings. The Company recorded the fair value of the embedded derivative as a derivative liability within deferred gains and other long-term liabilities and a debt discount within long-term debt and finance leases, less current maturities on its consolidated balance sheets. Upon the termination of the merger, the conversion settlement terms reverted to the original settlement terms of the indenture. As such, as of the date of the Termination Agreement, the Company qualified for the derivative accounting scope exception provided under ASC 815. During March 2024, the Company derecognized the remaining derivative liability as of the Termination Agreement execution date of $8.2 million, net of taxes, as an adjustment to additional paid-in-capital within the Company's consolidated balance sheets in accordance with ASC 815. The original debt discount will continue to be amortized through interest expense, using the effective interest rate method, over the remaining life of the instrument.

The convertible notes due 2026 are recorded within liabilities subject to compromise on the Company's consolidated balance sheets as of December 31, 2024. Refer to Note 3, Chapter 11 Proceedings, for additional information.
Long-term debt is comprised of the following:
As of
December 31, 2024December 31, 2023December 31, 2024December 31, 2023
(in millions)(weighted-average interest rates)
DIP term loan due in 2025$309.0 $— 11.82 %N/A
8.00% senior secured notes due in 2025 (2)
— 1,110.0 8.00 %8.00 %
Fixed-rate term loans due through 2039 (1)
972.2 1,093.3 6.44 %5.83 %
Unsecured term loans due through 2031136.3 136.3 1.00 %1.00 %
Fixed-rate class A 2015-1 EETC due through 2028
234.6 256.6 4.10 %4.10 %
Fixed-rate class B 2015-1 EETC due through 2024
— 40.0 4.45 %4.45 %
Fixed-rate class AA 2017-1 EETC due through 2030
160.3 172.2 3.38 %3.38 %
Fixed-rate class A 2017-1 EETC due through 2030
53.4 57.4 3.65 %3.65 %
Fixed-rate class B 2017-1 EETC due through 2026
44.7 48.2 3.80 %3.80 %
Convertible notes due in 2025 (2)
— 25.1 4.75 %4.75 %
Convertible notes due in 2026 (2)
— 500.0 1.00 %1.00 %
Revolving credit facility due in 2026300.0 — 6.67 %N/A
Long-term debt$2,210.5 $3,439.1 
Less current maturities436.3 315.3 
Less unamortized discount, net
13.2 69.0 
Total$1,761.0 $3,054.8 

(1) Includes obligations related to 18 aircraft recorded as failed sale leaseback transactions. Refer to Note 14, Leases for additional information.
(2) As of December 31, 2024, these debt instruments are recorded within liabilities subject to compromise on the Company's consolidated balance sheets. Refer to Note 3, Chapter 11 Proceedings, for additional information.
During the year ended December 31, 2024 and 2023, the Company made principal payments of $185.4 million and $337.5 million on its outstanding debt obligations, respectively.
Extinguishment of Debt
During the first quarter of 2024, the Company early extinguished $139.6 million of outstanding fixed-rate term loans related to five aircraft. In connection with this debt extinguishment, the Company recorded a gain of $15.0 million within loss (gain) on extinguishment of debt on its consolidated statement of operations. In addition, during the first quarter of 2024, the Company completed five sale leaseback transactions (on aircraft previously owned by the Company) of which, two resulted in operating leases and three would have been deemed finance leases resulting in failed sale leaseback transactions. As a result of the three failed sale leaseback transactions, the Company recorded the related debt of $123.5 million within current maturities of long-term debt and finance leases and long-term debt and finance leases, less current maturities. Refer to Note 14, Leases for additional information on the five sale leaseback transactions.
During the fourth quarter of 2024, the Company early extinguished $17.1 million of outstanding fixed-rate term loans related to the sale of 2 aircraft. For additional information, refer to Note 1, Summary of Significant Accounting Policies. In connection with this debt extinguishment, the Company recorded a loss of $0.1 million within loss (gain) on extinguishment of debt on its consolidated statements of operations.
At December 31, 2024, long-term debt principal payments for the next five years and thereafter are as follows:
December 31, 2024
(in millions)
2025$415.2 
2026429.1 
2027192.9 
2028257.2 
202984.8 
2030 and beyond831.3 
Total debt principal payments$2,210.5 


Interest Expense

Interest expense related to long-term debt and finance leases consists of the following:
 Twelve Months Ended December 31,
202420232022
(in thousands)
8.00% senior secured notes (1)
$92,621 $93,010 $47,954 
Fixed-rate term loans69,635 37,213 41,446 
Unsecured term loans1,365 1,363 1,363 
Class A 2015-1 EETC10,078 10,962 11,874 
Class B 2015-1 EETC446 1,954 2,312 
Class C 2015-1 EETC— 777 3,424 
Class AA 2017-1 EETC5,561 5,990 6,464 
Class A 2017-1 EETC2,005 2,159 2,330 
Class B 2017-1 EETC1,748 1,881 2,016 
Class C 2017-1 EETC— 522 4,367 
Convertible notes (2)
15,849 (3,778)(68)
Revolving credit facility4,501 — — 
DIP term loan812 — — 
Finance leases33 30 57 
Commitment and other fees1,340 1,655 2,162 
Amortization of deferred financing costs13,100 15,453 14,204 
Total$219,094 $169,191 $139,905 
(1) Includes $3.8 million, $4.2 million and $1.4 million of accretion and $88.8 million, $88.8 million and $46.5 million of interest expense for the twelve months ended December 31, 2024, 2023, and 2022, respectively.
(2) Includes $16.4 million, $14.3 million and $20.3 million of amortization of the discount for the convertible notes due 2026 as well as interest expense for the convertible notes due 2025 and 2026, offset by $0.5 million, $18.1 million and $20.3 million of favorable mark to market adjustments for the convertible notes due 2026 for the twelve months ended December 31, 2024, 2023, and 2022, respectively.
As of December 31, 2024 and 2023, the Company had a line of credit for $6.0 million and $20.1 million, respectively, related to corporate credit cards. Respectively, the Company had drawn $0.9 million and $1.5 million as of December 31, 2024 and 2023, which is included in accounts payable.
As of December 31, 2024, the Company had lines of credit with counterparties for derivatives, if any, in the amount of $3.5 million. As of December 31, 2023, the Company had lines of credit with counterparties for derivatives, if any, and physical fuel delivery in the amount of $25.0 million. As of December 31, 2024 and 2023, the Company had not drawn on these lines of credit. The Company is required to post collateral for any excess above the lines of credit if the derivatives, if any, are in a net liability position. As of December 31, 2024 and 2023, the Company did not have any outstanding derivatives.
v3.25.0.1
Leases
 12 Months Ended
Dec. 31, 2024
Leases [Abstract]  
Leases Leases
The Company leases aircraft, engines, airport terminals, maintenance and training facilities, aircraft hangars, commercial real estate and office and computer equipment, among other items. Certain of these leases include provisions for variable lease payments which are based on several factors, including, but not limited to, relative leases square footage, enplaned passengers, and airports' annual operating budgets. Due to the variable nature of the rates, these leases are not recorded on the Company's consolidated balance sheets as a right-of-use asset and lease liability. Lease terms are generally 4 to 18 years for aircraft and spare engines and up to 99 years for other leased equipment and property.

The filing of the Chapter 11 Cases on November 18, 2024 may have triggered an event of default under certain lease agreements of the Company, subject to the automatic stay resulting from the Chapter 11 Cases. For additional information on the Company's bankruptcy proceedings and its related automatic stay and other protections, refer to Note 3, Chapter 11 Proceedings.

As of December 31, 2024, the Company had a fleet consisting of 192 A320 family aircraft, excluding the 21 aircraft classified as assets held for sale on the Company's consolidated balance sheets. Refer to Note 1, Summary of Significant Accounting Policies for additional information on the aircraft recorded as assets held for sale. As of December 31, 2024, the Company had 146 aircraft financed under operating leases with lease term expirations between 2025 and 2042. In addition, the Company owned 49 aircraft of which, as of December 31, 2024, none were unencumbered. The Company also had 18 aircraft that would have been deemed finance leases resulting in failed sale leaseback transactions. The related finance obligation is recorded within long-term debt in the Company's consolidated balance sheets. Refer to Note 13, Debt and Other Obligations for additional information. The related asset is recorded within flight equipment in the Company's consolidated balance sheets. As of December 31, 2024, the Company also had 5 spare engines financed under operating leases with lease term expiration dates ranging from 2025 to 2033 and owned 32, of which 21 were pledged as collateral under the Company's revolving credit facility maturing in 2026.

Total rent expense for the years ended 2024, 2023 and 2022 was $855.5 million, $673.2 million and $537.9 million, respectively. Total rent expense for aircraft and engine operating leases for the years ended December 31, 2024, 2023 and 2022 was $541.9 million, $381.2 million and $282.4 million, respectively.

Under the terms of the lease agreements, the Company will continue to operate and maintain the aircraft. Payments under the majority of the lease agreements are fixed for the term of the lease. The lease agreements contain standard termination events, including termination upon a breach of the Company's obligations to make rental payments and upon any other material breach of the Company's obligations under the leases, and standard maintenance and return condition provisions. These return provisions are evaluated at inception of the lease and throughout the lease terms and are accounted for as either fixed or variable lease payments (depending on the nature of the lease return condition) when it is probable that such amounts will be incurred. When determining probability and estimated cost of lease return obligations, there are various other factors that need to be considered such as the contractual terms of the lease, the ability to swap engines or other aircraft components, current condition of the aircraft, the age of the aircraft at lease expiration, utilization of engines and other components, the extent of repairs needed at return, return locations, current configuration of the aircraft and cost of repairs and materials at the time of return. Management assesses the factors listed above and the need to accrue lease return costs throughout the lease as facts and circumstances warrant an assessment. The Company expects lease return costs will increase as individual aircraft lease agreements approach their respective termination dates and the Company begins to accrue the estimated cost of return conditions for the corresponding aircraft. Upon a termination of the lease due to a breach by the Company, the Company would be liable for standard contractual damages, possibly including damages suffered by the lessor in connection with remarketing the aircraft or while the aircraft is not leased to another party.
Aircraft rent expense consists of monthly lease rents for aircraft and spare engines under the terms of the Company's aircraft and spare engine lease agreements recognized on a straight-line basis. Supplemental rent, recorded within aircraft rent expense, is primarily made up of probable and estimable return condition obligations, lease return costs adjustments for aircraft and engines purchased off lease or lease extensions or amendments. The Company expensed $36.2 million, $14.0 million and $16.5 million of supplemental rent recorded within aircraft rent during 2024, 2023 and 2022, respectively.
During the twelve months ended December 31, 2024, the Company took delivery of 19 new aircraft under direct operating leases, 8 new aircraft under sale leaseback transactions, 3 engines purchased with cash and purchased 1 spare engine off lease.
Under Topic 842, gains and losses on sale leaseback transactions, subject to adjustment for off-market terms, are recognized immediately and recorded within loss (gain) on disposal of assets on the Company's consolidated statements of
operations. Refer to Note 5, Loss (gain) on Disposal of Assets for additional information on the losses recorded related to the sale leaseback transactions entered into during the twelve months ended December 31, 2024, 2023 and 2022.
As of December 31, 2024, the Company's finance lease obligations relate to the lease of computer equipment used by the Company's flight crew and office equipment. Payments under these finance lease agreements are fixed for terms generally ranging from 4 to 5 years. Finance lease assets are recorded within property and equipment and the related liabilities are recorded within long-term debt and finance leases in the Company's consolidated balance sheets.
During the fourth quarter of 2019, the Company purchased an 8.5-acre parcel of land for $41.0 million and entered into a 99-year lease agreement for the lease of a 2.6-acre parcel of land, in Dania Beach, Florida, where the Company built its new headquarters campus and a 200-unit residential building. As of December 31, 2024, the 8.5-acre parcel of land and related construction costs were capitalized within other property and equipment on the Company's consolidated balance sheets. The 99-year lease was determined to be an operating lease and is recorded within operating lease right-of-use asset and operating lease liability on the Company's consolidated balance sheets. Operating lease commitments related to this lease are included in the table below within property facility leases.
The following table provides details of the Company's future minimum lease payments under finance lease liabilities and operating lease liabilities recorded on the Company's consolidated balance sheets as of December 31, 2024. The table does not include commitments that are contingent on events or other factors that are currently uncertain and unknown.
Finance LeasesOperating LeasesTotal Operating and Finance Lease Obligations
Aircraft and Spare Engine LeasesProperty Facility Leases
(in thousands)
2025$219 $564,040 $5,047 $569,306 
2026141 538,911 4,939 543,991 
202793 522,951 4,140 527,184 
202867 502,185 2,757 505,009 
20296 486,881 2,129 489,016 
2030 and thereafter— 4,842,905 141,638 4,984,543 
Total minimum lease payments$526 $7,457,873 $160,650 $7,619,049 
Less amount representing interest50 2,893,031 132,590 3,025,671 
Present value of minimum lease payments$476 $4,564,842 $28,060 $4,593,378 
Less current portion195 254,521 3,275 257,991 
Long-term portion$281 $4,310,321 $24,785 $4,335,387 
Commitments related to the Company's noncancellable short-term operating leases not recorded on the Company's consolidated balance sheets are expected to be $2.8 million for 2025 and none for 2026 and beyond.
The table below presents information for lease costs related to the Company's finance and operating leases:
Year Ended December 31,
20242023
(in thousands)
Finance lease cost
Amortization of leased assets$277 $451 
Interest of lease liabilities33 30 
Operating lease cost
Operating lease cost (1)
517,016 377,505 
Short-term lease cost (1)
37,294 39,916 
Variable lease cost (1)
272,087 227,030 
Total lease cost$826,707 $644,932 
(1) Expenses are classified within aircraft rent and landing fees and other rents on the Company's consolidated statements of operations.
The table below presents lease-related terms and discount rates as of December 31, 2024:
December 31, 2024December 31, 2023
Weighted-average remaining lease term
Operating leases15.1 years14.8 years
Finance leases2.9 years2.3 years
Weighted-average discount rate
Operating leases7.11 %6.84 %
Finance leases5.91 %4.25 %
Leases Leases
The Company leases aircraft, engines, airport terminals, maintenance and training facilities, aircraft hangars, commercial real estate and office and computer equipment, among other items. Certain of these leases include provisions for variable lease payments which are based on several factors, including, but not limited to, relative leases square footage, enplaned passengers, and airports' annual operating budgets. Due to the variable nature of the rates, these leases are not recorded on the Company's consolidated balance sheets as a right-of-use asset and lease liability. Lease terms are generally 4 to 18 years for aircraft and spare engines and up to 99 years for other leased equipment and property.

The filing of the Chapter 11 Cases on November 18, 2024 may have triggered an event of default under certain lease agreements of the Company, subject to the automatic stay resulting from the Chapter 11 Cases. For additional information on the Company's bankruptcy proceedings and its related automatic stay and other protections, refer to Note 3, Chapter 11 Proceedings.

As of December 31, 2024, the Company had a fleet consisting of 192 A320 family aircraft, excluding the 21 aircraft classified as assets held for sale on the Company's consolidated balance sheets. Refer to Note 1, Summary of Significant Accounting Policies for additional information on the aircraft recorded as assets held for sale. As of December 31, 2024, the Company had 146 aircraft financed under operating leases with lease term expirations between 2025 and 2042. In addition, the Company owned 49 aircraft of which, as of December 31, 2024, none were unencumbered. The Company also had 18 aircraft that would have been deemed finance leases resulting in failed sale leaseback transactions. The related finance obligation is recorded within long-term debt in the Company's consolidated balance sheets. Refer to Note 13, Debt and Other Obligations for additional information. The related asset is recorded within flight equipment in the Company's consolidated balance sheets. As of December 31, 2024, the Company also had 5 spare engines financed under operating leases with lease term expiration dates ranging from 2025 to 2033 and owned 32, of which 21 were pledged as collateral under the Company's revolving credit facility maturing in 2026.

Total rent expense for the years ended 2024, 2023 and 2022 was $855.5 million, $673.2 million and $537.9 million, respectively. Total rent expense for aircraft and engine operating leases for the years ended December 31, 2024, 2023 and 2022 was $541.9 million, $381.2 million and $282.4 million, respectively.

Under the terms of the lease agreements, the Company will continue to operate and maintain the aircraft. Payments under the majority of the lease agreements are fixed for the term of the lease. The lease agreements contain standard termination events, including termination upon a breach of the Company's obligations to make rental payments and upon any other material breach of the Company's obligations under the leases, and standard maintenance and return condition provisions. These return provisions are evaluated at inception of the lease and throughout the lease terms and are accounted for as either fixed or variable lease payments (depending on the nature of the lease return condition) when it is probable that such amounts will be incurred. When determining probability and estimated cost of lease return obligations, there are various other factors that need to be considered such as the contractual terms of the lease, the ability to swap engines or other aircraft components, current condition of the aircraft, the age of the aircraft at lease expiration, utilization of engines and other components, the extent of repairs needed at return, return locations, current configuration of the aircraft and cost of repairs and materials at the time of return. Management assesses the factors listed above and the need to accrue lease return costs throughout the lease as facts and circumstances warrant an assessment. The Company expects lease return costs will increase as individual aircraft lease agreements approach their respective termination dates and the Company begins to accrue the estimated cost of return conditions for the corresponding aircraft. Upon a termination of the lease due to a breach by the Company, the Company would be liable for standard contractual damages, possibly including damages suffered by the lessor in connection with remarketing the aircraft or while the aircraft is not leased to another party.
Aircraft rent expense consists of monthly lease rents for aircraft and spare engines under the terms of the Company's aircraft and spare engine lease agreements recognized on a straight-line basis. Supplemental rent, recorded within aircraft rent expense, is primarily made up of probable and estimable return condition obligations, lease return costs adjustments for aircraft and engines purchased off lease or lease extensions or amendments. The Company expensed $36.2 million, $14.0 million and $16.5 million of supplemental rent recorded within aircraft rent during 2024, 2023 and 2022, respectively.
During the twelve months ended December 31, 2024, the Company took delivery of 19 new aircraft under direct operating leases, 8 new aircraft under sale leaseback transactions, 3 engines purchased with cash and purchased 1 spare engine off lease.
Under Topic 842, gains and losses on sale leaseback transactions, subject to adjustment for off-market terms, are recognized immediately and recorded within loss (gain) on disposal of assets on the Company's consolidated statements of
operations. Refer to Note 5, Loss (gain) on Disposal of Assets for additional information on the losses recorded related to the sale leaseback transactions entered into during the twelve months ended December 31, 2024, 2023 and 2022.
As of December 31, 2024, the Company's finance lease obligations relate to the lease of computer equipment used by the Company's flight crew and office equipment. Payments under these finance lease agreements are fixed for terms generally ranging from 4 to 5 years. Finance lease assets are recorded within property and equipment and the related liabilities are recorded within long-term debt and finance leases in the Company's consolidated balance sheets.
During the fourth quarter of 2019, the Company purchased an 8.5-acre parcel of land for $41.0 million and entered into a 99-year lease agreement for the lease of a 2.6-acre parcel of land, in Dania Beach, Florida, where the Company built its new headquarters campus and a 200-unit residential building. As of December 31, 2024, the 8.5-acre parcel of land and related construction costs were capitalized within other property and equipment on the Company's consolidated balance sheets. The 99-year lease was determined to be an operating lease and is recorded within operating lease right-of-use asset and operating lease liability on the Company's consolidated balance sheets. Operating lease commitments related to this lease are included in the table below within property facility leases.
The following table provides details of the Company's future minimum lease payments under finance lease liabilities and operating lease liabilities recorded on the Company's consolidated balance sheets as of December 31, 2024. The table does not include commitments that are contingent on events or other factors that are currently uncertain and unknown.
Finance LeasesOperating LeasesTotal Operating and Finance Lease Obligations
Aircraft and Spare Engine LeasesProperty Facility Leases
(in thousands)
2025$219 $564,040 $5,047 $569,306 
2026141 538,911 4,939 543,991 
202793 522,951 4,140 527,184 
202867 502,185 2,757 505,009 
20296 486,881 2,129 489,016 
2030 and thereafter— 4,842,905 141,638 4,984,543 
Total minimum lease payments$526 $7,457,873 $160,650 $7,619,049 
Less amount representing interest50 2,893,031 132,590 3,025,671 
Present value of minimum lease payments$476 $4,564,842 $28,060 $4,593,378 
Less current portion195 254,521 3,275 257,991 
Long-term portion$281 $4,310,321 $24,785 $4,335,387 
Commitments related to the Company's noncancellable short-term operating leases not recorded on the Company's consolidated balance sheets are expected to be $2.8 million for 2025 and none for 2026 and beyond.
The table below presents information for lease costs related to the Company's finance and operating leases:
Year Ended December 31,
20242023
(in thousands)
Finance lease cost
Amortization of leased assets$277 $451 
Interest of lease liabilities33 30 
Operating lease cost
Operating lease cost (1)
517,016 377,505 
Short-term lease cost (1)
37,294 39,916 
Variable lease cost (1)
272,087 227,030 
Total lease cost$826,707 $644,932 
(1) Expenses are classified within aircraft rent and landing fees and other rents on the Company's consolidated statements of operations.
The table below presents lease-related terms and discount rates as of December 31, 2024:
December 31, 2024December 31, 2023
Weighted-average remaining lease term
Operating leases15.1 years14.8 years
Finance leases2.9 years2.3 years
Weighted-average discount rate
Operating leases7.11 %6.84 %
Finance leases5.91 %4.25 %
v3.25.0.1
Defined Contribution 401(k) Plan
 12 Months Ended
Dec. 31, 2024
Retirement Benefits [Abstract]  
Defined Contribution 401(k) Plan Defined Contribution 401(k) Plan
The Company sponsors three defined contribution 401(k) plans, Spirit Airlines, Inc. Employee Retirement Savings Plan (first plan), Spirit Airlines, Inc. Pilots’ Retirement Savings Plan (second plan) and Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan (third plan). The first plan is for all employees that are not covered by the pilots’ collective bargaining agreement, who have at least 60 days of service and have attained the age of 21.
The second plan is for the Company’s pilots, and contains the same service requirements as the first plan. Beginning on March 1, 2018, the Company contributed 11% of the individual pilot's annual compensation, regardless of the pilot's contributions to the plan. The Company's contribution increased by 1% on an annual basis each March until 2022, at which time the contribution was 15%. Beginning on January 1, 2024, the Company's contribution increased to 16%.
Employer contributions made to all plans were $128.5 million, $112.4 million and $88.9 million in 2024, 2023 and 2022, respectively, and were included within salaries, wages and benefits in the accompanying consolidated statements of operations.
v3.25.0.1
Income Taxes
 12 Months Ended
Dec. 31, 2024
Income Tax Disclosure [Abstract]  
Income Taxes Income Taxes
Significant components of the provision for income taxes from continuing operations are as follows:
 Year Ended December 31,
202420232022
(in thousands)
Current:
Federal$(5,438)$5,449 $— 
State and local(40)1,309 327 
Foreign3,485 1,350 1,695 
Total current expense (benefit)(1,993)8,108 2,022 
Deferred:
Federal(54,922)(115,905)(141,251)
State and local(3,293)(3,334)(7,360)
Total deferred expense (benefit)(58,215)(119,239)(148,611)
Total income tax expense (benefit)$(60,208)$(111,131)$(146,589)

The income tax provision differs from that computed at the federal statutory corporate tax rate as follows:
 Year Ended December 31,
202420232022
Expected provision at federal statutory tax rate21.0 %21.0 %21.0 %
State tax expense, net of federal benefit1.3 %1.5 %1.6 %
Permanent tax differences(1.6)%(1.3)%(0.6)%
Valuation allowance(16.1)%(1.2)%(0.8)%
Other0.1 %(0.1)%(0.3)%
Total income tax expense (benefit)4.7 %19.9 %20.9 %

The Company accounts for income taxes using the asset and liability method. Deferred taxes are recorded based on differences between the consolidated financial statement basis and tax basis of assets and liabilities and available tax loss and credit carryforwards. At December 31, 2024 and 2023, the significant components of the Company's deferred taxes consisted of the following:
 December 31,
20242023
(in thousands)
Deferred tax assets:
Income tax credits$2,441 $4,298 
Net operating losses437,400 328,977 
Deferred revenue22,641 25,924 
Nondeductible accruals29,936 32,899 
Deferred manufacturing credits13,415 14,556 
Loan liability140,313 115,161 
Operating lease liability1,053,684 797,778 
Interest expense70,011 51,305 
Other17,496 38,910 
Valuation allowance(226,389)(17,654)
Deferred tax assets1,560,948 $1,392,154 
Deferred tax liabilities:
Property, plant and equipment513,028 612,571 
Accrued aircraft and engine maintenance54,574 70,997 
Right-of-use asset1,042,099 803,232 
Other3,174 13,115 
Deferred tax liabilities1,612,875 1,499,915 
Net deferred tax assets (liabilities)$(51,927)$(107,761)

In assessing the realizability of the deferred tax assets, management considered whether it is more likely than not that some or all of the deferred tax assets would be realized. In evaluating the Company’s ability to utilize its deferred tax assets, it considered all available evidence, both positive and negative, in determining future taxable income on a jurisdiction by jurisdiction basis. As of December 31, 2024 and 2023, the Company had a valuation allowance of $226.4 million and $17.7 million, respectively, primarily against deferred tax assets related to federal and state net operating loss carryforwards.
As of December 31, 2024, the Company had $0.9 million of foreign tax credits, $1.4 million of general business tax credits, $1.9 billion of federal net operating loss and $862.0 million of state net operating loss available, that may be applied against future tax liabilities. The foreign tax credits will begin to expire in 2025, the state net operating losses will begin to expire in 2027, the general business credits will begin to expire in 2038 and there is no expiration of federal net operating losses.
For tax years ended December 31, 2024, 2023 and 2022, the Company did not recognize any liabilities for uncertain tax positions nor any interest and penalties on unrecognized tax benefits.
For tax years 2024, 2023 and 2022, all income for the Company is subject to domestic income taxes.
The Company files its tax returns as prescribed by the tax laws of the jurisdictions in which it operates. The Company's federal income tax returns for 2021 through 2023 tax years are still subject to examination in the United States. Various state and foreign jurisdiction tax years also remain open to examination. The Company believes that any potential assessment would be immaterial to its consolidated financial statements.
v3.25.0.1
Commitments and Contingencies
 12 Months Ended
Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies Commitments and Contingencies
Aircraft-Related Commitments and Financing Arrangements
The Company’s contractual purchase commitments consist primarily of aircraft and engine acquisitions through manufacturers and aircraft leasing companies. On April 3, 2024, the Company entered into Amendment No. 7 to the A320 NEO Family Purchase Agreement, dated as of December 20, 2019 with Airbus S.A.S. ("Airbus"). The Amendment (i) defers all aircraft on order that are scheduled to be delivered in the second quarter of 2025 through the end of 2026 to 2030 through 2031, and (ii) adjusts the delivery periods of option aircraft from 2027 through 2029 to 2029 through 2031. On July 30, 2024, the Company entered into a direct lease transaction (the “Direct Lease Transaction”) with AerCap Holdings N.V. (“AerCap”) for 36 aircraft scheduled for delivery between 2027 and 2028 (the “Leased Aircraft”) which were originally part of the Company’s order book. Under the terms of the transaction, AerCap will assume the delivery positions for the Leased Aircraft and related PDP obligations. AerCap has agreed to lease each Leased Aircraft to the Company upon delivery by Airbus. Each of the leases will have fixed rent payments.
As of December 31, 2024, the Company's firm aircraft orders consisted of 55 A320 family aircraft with Airbus, including A320neos and A321neos, with deliveries expected through 2031. As of December 31, 2024, the Company had secured financing for three aircraft, scheduled for delivery from Airbus through 2025, which will be financed through sale leaseback transactions. The Company did not have financing commitments in place for the remaining 52 Airbus aircraft currently on firm order through 2031. However, the Company has signed a financing letter of agreement with Airbus which provides backstop financing for a majority of the aircraft included in the Airbus Purchase Agreement. The agreement provides a standby credit facility in the form of senior secured mortgage debt financing. The contractual purchase amounts for all aircraft orders from Airbus as of December 31, 2024 are included within the purchase commitments below. In addition, rent commitments related to aircraft that will be financed through sale leaseback transactions are included within the aircraft rent commitments below.
In connection with the Direct Lease Transaction, on July 30, 2024, the Company entered into a transaction (the “PDP Transaction”) whereby certain PDPs with respect to 52 aircraft currently scheduled for delivery between 2029 and 2031 (the “Other Aircraft”), subject to the Airbus Purchase Agreement were paid to the Company (the “Funded PDPs”) at closing of the PDP Transaction. The Direct Lease Transaction and the PDP Transaction, in the aggregate, resulted in approximately $186 million of additional cash paid to the Company.
During the third quarter of 2021, the Company entered into an Engine Purchase Support Agreement which requires the Company to purchase a certain number of spare engines in order to maintain a contractual ratio of spare engines to aircraft in the fleet. As of December 31, 2024, the Company is committed to purchase 16 PW1100G-JM spare engines, with deliveries through 2031.
As of December 31, 2024, purchase commitments for the Company's aircraft and engine orders, including estimated amounts for contractual price escalations and pre-delivery payments, were expected to be $153.3 million in 2025, $12.3 million in 2026, $183.0 million in 2027, $297.8 million in 2028, $1,124.3 million in 2029 and $1,857.8 million in 2030 and beyond.
During the third quarter of 2019, the United States announced its decision to levy tariffs on certain imports from the European Union, including commercial aircraft and related parts. These tariffs include aircraft and other parts that the Company is already contractually obligated to purchase including those reflected above. In June 2021, the United States Trade Representative announced that the United States and European Union had agreed to suspend reciprocal tariffs on large civilian aircraft for five years, pending discussions to resolve their trade dispute. For further discussion on this topic, please refer to "Risk Factors - Risks Related to Our Business - Any tariffs imposed on commercial aircraft and related parts imported from outside the United States may have a material adverse effect on our fleet, business, financial condition and our results of operations."
In addition to the Airbus Purchase Agreement, as of December 31, 2024, the Company had agreements in place for 39 aircraft to be financed through direct leases with third-party lessors with deliveries scheduled from 2025 through 2028. As of December 31, 2024, aircraft rent commitments for future aircraft deliveries to be financed under direct leases from third-party lessors and sale leaseback transactions are expected to be $20.5 million in 2025, $27.1 million in 2026, $88.3 million in 2027, $183.3 million in 2028, $229.4 million in 2029, and $2,204.1 million in 2030 and beyond.
Interest commitments related to the secured debt financing of 67 aircraft as of December 31, 2024 are $72.3 million in 2025, $77.5 million in 2026, $71.4 million in 2027, $63.2 million in 2028, $56.8 million in 2029, and $102.8 million in 2030 and beyond. As of December 31, 2024, interest commitments related to the Company's unsecured term loans, revolving credit facility and DIP term loan are $3.8 million in 2025, $3.4 million in 2026, $3.4 million in 2027, $3.4 million in 2028, $3.4 million in 2029, and $3.7 million in 2030 and beyond. For principal commitments related to the Company's outstanding debt obligations, refer to Note 13, Debt and Other Obligations.
In addition, the principal related to the Company's 8.00% senior secured notes due 2025, convertible notes due 2025 and convertible notes due 2026 are recorded within liabilities subject to compromise on the Company's consolidated balance sheets as of the Petition Date. Refer to Note 3, Chapter 11 Proceedings, for additional information on the Company's bankruptcy proceedings.
Other Commitments
The Company is contractually obligated to pay the following minimum guaranteed payments for its reservation system and other miscellaneous subscriptions and services as of December 31, 2024: $41.1 million in 2025, $24.0 million in 2026, $18.5 million in 2027, $2.0 million in 2028, $0.1 million in 2029, and none in 2030 and beyond. The Company's reservation system contract expires in 2028.
Litigation and Assessments
The Company is subject to commercial litigation claims and to administrative and regulatory proceedings and reviews that may be asserted or maintained from time to time. The Company believes the ultimate outcome of such lawsuits, proceedings and reviews will not, individually or in the aggregate, have a material adverse effect on its financial position, liquidity or results of operations. In making a determination regarding accruals, using available information, the Company evaluates the likelihood of an unfavorable outcome in legal or regulatory proceedings and assessments to which the Company is a party and records a loss contingency when it is probable a liability has been incurred and the amount of the loss can be reasonably estimated. These subjective determinations are based on the status of such legal or regulatory proceedings, the merits of the Company's defenses, and consultation with legal counsel. Actual outcomes of these legal and regulatory proceedings may materially differ from the Company's current estimates. It is possible that resolution of one or more of the legal matters currently pending or threatened could result in losses material to the Company's consolidated results of operations, liquidity, or financial condition.
In 2017, the Company was sued in the Eastern District of New York ("EDNY") in a purported class action, Cox, et al. v. Spirit Airlines, Inc., alleging state-law claims of breach of contract, unjust enrichment and fraud relating to the Company's practice of charging fees for ancillary products and services. In June 2023, the Company reached a tentative settlement in mediation for a maximum amount of $8.3 million. The EDNY issued a preliminary approval order on September 21, 2023, and the final approval hearing was held on December 11, 2023. The total amount paid depends on a number of factors, including participation of class members and any conditions on the settlement approved by the EDNY. As of December 31, 2023, the Company's best estimate of the probable loss associated with the settlement was $6.0 million recorded in other operating expenses within its consolidated statements of operations. During the first and third quarters of 2024, the estimated probable loss recorded was reduced by $1.4 million and $0.3 million, respectively. As of December 31, 2024, the total obligation of $4.3 million related to this matter has been paid.
On February 27, 2023, ALPA filed a grievance against the Company claiming that it violated the collective bargaining agreement (“CBA”) by excluding its pilots from the Company's retention award programs granted as part of the Former Frontier Merger Agreement and the Merger Agreement with JetBlue. On September 8, 2023, the Company filed a motion to dismiss the grievance, as it does not believe that ALPA filed the grievance within the timeline set forth in the CBA. As of December 31, 2024, the grievance is postponed indefinitely. The potential outcomes of this claim cannot be determined and an estimate of the reasonably possible loss or range of loss cannot be made.
Following an audit by the Internal Revenue Service ("IRS") related to the collection of federal excise taxes on optional passenger seat selection charges covering the period of the second quarter 2018 through the fourth quarter 2020, on March 31, 2022, the Company was assessed $34.9 million. On July 19, 2022, the assessment was reduced to $27.5 million. The Company believes it has defenses available and intends to challenge the assessment; therefore, the Company believes a loss in this matter is not probable and has not recognized a loss contingency.
Employees
The Company has six union-represented employee groups that together represent approximately 84% of all employees at December 31, 2024. The table below sets forth the Company's employee groups and status of the CBAs.

Employee Groups  Representative  
Amendable Date (1)
Percentage of Workforce
Pilots  
Air Line Pilots Association, International (ALPA) (2)
  March 202427%
Flight Attendants  Association of Flight Attendants (AFA-CWA)  January 202644%
Dispatchers  Professional Airline Flight Control Association (PAFCA)  August 20261%
Ramp Service AgentsInternational Association of Machinists and Aerospace Workers (IAMAW)November 20263%
Passenger Service AgentsTransport Workers Union of America (TWU)February 20273%
Aircraft Maintenance Technicians
Aircraft Mechanics Fraternal Association (AMFA) (2)
N/A 6%

(1) Subject to standard early opener provisions.
(2) Collective bargaining agreement is currently under negotiation.

In August 2022, the Company's aircraft maintenance technicians ("AMTs") voted to be represented by AMFA as their collective bargaining agent. In May 2024, the parties began negotiations with a NMB mediation, and those discussions are ongoing. As of December 31, 2024, the Company had approximately 640 AMTs.

In July 2024, the Company reached an agreement with PAFCA for a new two-year agreement, which was ratified by PAFCA members on August 10, 2024. The ratified agreement includes increased pay rates.
In March 2024, ALPA provided notice to the Company that it intended to amend its CBA with its pilots. In July 2024, the parties began negotiations, and those discussions are ongoing.
To ensure the Company has the right level of resources to meet its reduced aircraft capacity levels, primarily due to increased AOG days from GTF engine issues and the sale of aircraft, it furloughed approximately 170 pilots, effective September 1, 2024, and announced in the fourth quarter of 2024 that, effective January 31, 2025, it would furlough approximately 300 additional pilots to align with its projected flight volume for 2025. During the third and fourth quarters of 2024, the Company recorded $1.4 million and $3.5 million, respectively, in expenses related to these furloughs. These expenses were recorded within salaries, wages and benefits on the Company's consolidated statements of operations. In addition, in January 2025, as part of the Company's ongoing efforts to optimize and enhance efficiencies, it made the decision to eliminate approximately 200 positions from various departments.
The Company is self-insured for health care claims, subject to a stop-loss policy, for eligible participating employees and qualified dependent medical claims, subject to deductibles and limitations. The Company’s liabilities for claims incurred but not reported are determined based on an estimate of the ultimate aggregate liability for claims incurred. The estimate is calculated from actual claim rates and adjusted periodically as necessary. The Company has accrued $11.6 million and $9.1 million, for health care claims as of December 31, 2024, and 2023, respectively, recorded within other current liabilities on the Company's consolidated balance sheet.
v3.25.0.1
Fair Value Measurements
 12 Months Ended
Dec. 31, 2024
Fair Value Disclosures [Abstract]  
Fair Value Measurements Fair Value Measurements
Under ASC 820, "Fair Value Measurements and Disclosures", disclosures relating to how fair value is determined for assets and liabilities are required, and a hierarchy for which these assets and liabilities must be grouped is established, based on significant levels of inputs, as follows:
Level 1—Quoted prices in active markets for identical assets or liabilities.
Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes several valuation techniques in order to assess the fair value of the Company’s financial assets and liabilities.
Long-term Debt
    The estimated fair value of the Company's secured notes, term loan debt agreements and revolving credit facility has been determined to be Level 3 as certain inputs used to determine the fair value of these agreements are unobservable. The Company utilizes a discounted cash flow method to estimate the fair value of the Level 3 long-term debt. The estimated fair value of the Company's publicly and non-publicly held EETC debt agreements and the Company's convertible notes has been determined to be Level 2 as the Company utilizes quoted market prices in markets with low trading volumes to estimate the fair value of its Level 2 long-term debt.
    The carrying amounts and estimated fair values of the Company's long-term debt at December 31, 2024 and December 31, 2023, were as follows:
As of December 31,
20242023
 Carrying ValueEstimated Fair ValueCarrying ValueEstimated Fair ValueFair value level hierarchy
(in millions)
DIP term loans$309.0 $309.0 $— $— Level 3
Fixed-rate term loans972.2 970.7 1,093.3 1,099.9 Level 3
Unsecured term loans136.3 130.4 136.3 128.3 Level 3
2015-1 EETC Class A 234.6 215.8 256.6 230.8 Level 2
2015-1 EETC Class B — — 40.0 39.4 Level 2
2017-1 EETC Class AA160.3 140.4 172.2 149.6 Level 2
2017-1 EETC Class A53.4 45.8 57.4 48.5 Level 2
2017-1 EETC Class B44.7 40.5 48.2 42.9 Level 2
Revolving credit facility due 2026300.0 300.0 — — Level 3
Total long-term debt$2,210.5 $2,152.6 $1,804.0 $1,739.4 
8.00% senior secured notes
$1,110.0 $1,117.9 $1,110.0 $1,121.9 Level 3
4.75% convertible notes due 2025
25.1 8.8 25.1 42.3 Level 2
1.00% convertible notes due 2026
500.0 166.4 500.0 349.9 Level 2
Total liabilities subject to compromise$1,635.1 $1,293.1 $1,635.1 $1,514.1 

Cash and Cash Equivalents

Cash and cash equivalents at December 31, 2024 and December 31, 2023 are comprised of liquid money market funds and cash and are categorized as Level 1 instruments. The Company maintains cash with various high-quality financial institutions.

Restricted Cash

Restricted cash is comprised of cash held in account subject to account control agreements or otherwise pledged as collateral against the Company's letters of credit and is categorized as a Level 1 instrument. As of December 31, 2024, the Company had a $68.0 million standby letter of credit secured by $68.0 million of restricted cash, of which $58.8 million were issued letters of credit. In addition, the Company had $50.0 million of restricted cash held in an account subject to a control agreement under its credit card processing agreement, $44.4 million of restricted cash held in accounts subject to control agreements to be used for the payment of interest and fees on the Company's 8.00% senior secured notes and $6.0 million in pledged cash pursuant to its corporate credit cards.
Short-term Investment Securities
Short-term investment securities at December 31, 2024 and December 31, 2023 are classified as available-for-sale and generally consist of U.S. Treasury and U.S. government agency securities with contractual maturities of twelve months or less. The Company's short-term investment securities are categorized as Level 1 instruments, as the Company uses quoted market prices in active markets when determining the fair value of these securities. For additional information, refer to Note 8, Short-term Investment Securities.

Assets Held for Sale
The Company's assets held for sale as of December 31, 2024 primarily consisted of 21 A320ceo and A321ceos aircraft currently under contract for sale. Currently, these aircraft are not being utilized within the operation and are available for immediate sale. For additional information, refer to Note 1, Summary of Significant Accounting Policies. The Company's assets held for sale as of December 31, 2023 primarily consisted of rotable aircraft parts. The assets are measured at the lower of the carrying amount or fair value less cost to sell and a loss is recognized for any initial adjustment of the asset’s carrying amount to fair value less cost to sell. Such valuations include estimations of fair values and incremental direct costs to transact a sale. The fair values were determined using Level 3 fair value inputs primarily based on the agreed upon sales price for each aircraft.
Derivative Liability

The Merger Agreement with JetBlue modified the settlement terms for any conversions of the convertible notes due 2026 such that, the conversion option, which is an embedded derivative, did not qualify for the derivative accounting scope exception provided under ASC 815. As such, the Company bifurcated the fair value of the conversion option of the convertible notes due 2026 as a derivative liability with subsequent changes in fair value recorded in earnings. Refer to Note 13, Debt and Other Obligations, for additional information.

The Company recorded the fair value of the embedded derivative as a derivative liability within deferred gains and other long-term liabilities on its consolidated balance sheets. The fair value of the derivative liability was estimated as the difference in value of the traded price of the convertible notes, including the conversion option and the value of the convertible notes in the absence of the conversion option (the debt component). The value of the debt component was estimated using a discounted cash flow analysis with a yield calibrated to the traded price of the convertible notes. The change in fair value of the derivative liability is recorded within interest expense on the Company's consolidated statements of operations.

Upon the termination of the merger, the conversion settlement terms reverted to the original settlement terms of the indenture. The Company performed a discounted cash flow analysis to reassess the fair value of the derivative liability as of March 3, 2024, the day prior to the announcement of the termination of the Merger Agreement. During the first quarter of 2024, the Company recorded $0.5 million in favorable mark to market adjustments related to the change in fair value of the derivative liability through the date of termination. During the twelve months ended December 31, 2023, the Company recorded $18.1 million in favorable mark to market adjustments related to the change in fair value of the derivative liability. The fair value of the derivative liability has been determined to be Level 2, as observable inputs were used to determine the fair value of derivative liability. For additional information, refer to Note 13, Debt and Other Obligations.

In addition, as of the date of the Termination Agreement, the Company reclassified the remaining derivative liability as of the Termination Agreement execution date of $8.2 million, net of taxes, to additional paid-in-capital within the Company's consolidated balance sheets.

Assets and liabilities measured at gross fair value on a recurring basis are summarized below:
 
 Fair Value Measurements as of December 31, 2024
 TotalLevel
1		Level
2		Level
3
(in millions)
Cash and cash equivalents$902.1 $902.1 $— $— 
Restricted cash168.4 168.4 — — 
Short-term investment securities118.3 118.3 — — 
Assets held for sale463.0 — — 463.0 
Total assets$1,651.8 $1,188.8 $— $463.0 
Total liabilities$— $— $— $— 
 
 Fair Value Measurements as of December 31, 2023
 TotalLevel
1		Level
2		Level
3
(in millions)
Cash and cash equivalents$865.2 $865.2 $— $— 
Restricted cash119.4 119.4 — — 
Short-term investment securities112.5 112.5 — — 
Assets held for sale1.8 — — 1.8 
Total assets$1,098.9 $1,097.1 $— $1.8 
Derivative liability$11.1 $— $11.1 $— 
Total liabilities$11.1 $— $11.1 $— 
The Company had no transfers of assets or liabilities between any of the above levels during the years ended December 31, 2024 or December 31, 2023.
v3.25.0.1
Operating Segments and Related Disclosures
 12 Months Ended
Dec. 31, 2024
Segment Reporting [Abstract]  
Operating Segments and Related Disclosures Operating Segments and Related Disclosures
The Company operates in a single reportable segment that provides air transportation to passengers. The Company’s Chief Operating Decision Maker (“CODM”) regularly evaluates the Company’s consolidated operating income (loss) to make decisions regarding resource allocation and performance assessment. Additionally, significant segment expenses provided to the CODM align with those shown in the consolidated statement of operations. Ted Christie, President and Chief Executive Officer, serves as the Company’s CODM and is responsible for overseeing operating performance, allocating resources and regularly communicating with executive team on these matters. For more information on the consolidated operating results of the Company’s single reportable segment, refer to the Company’s consolidated statements of operations.

Operating revenues by geographic region as defined by the Department of Transportation ("DOT") area are summarized below:
202420232022
(in millions)
DOT—Domestic$4,358.2 $4,676.1 $4,371.8 
DOT—Latin America and Caribbean555.2 686.4 696.6 
Total$4,913.4 $5,362.5 $5,068.4 
During 2024, 2023 and 2022, no revenue from any one foreign country represented greater than 4% of the Company’s total passenger revenue. The Company attributes operating revenues by geographic region based upon the origin and destination of each passenger flight segment. The Company’s tangible assets consist primarily of flight equipment, which are mobile across geographic markets and, therefore, have not been allocated.
v3.25.0.1
Pay vs Performance Disclosure - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Pay vs Performance Disclosure      
Net income (loss) $ (1,229,495) $ (447,464) $ (554,150)
v3.25.0.1
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2024
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.25.0.1
Insider Trading Policies and Procedures
 12 Months Ended
Dec. 31, 2024
Insider Trading Policies and Procedures [Line Items]  
Insider Trading Policies and Procedures Adopted true
v3.25.0.1
Cybersecurity Risk Management and Strategy Disclosure
 12 Months Ended
Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]  
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]
The Company’s cybersecurity program is designed to secure the continuity of operations and protect the privacy of company, guest and team member data. The Company uses multiple layers of security controls and unique threat intelligence within the “Center for Internet Security v8 Cybersecurity Framework” across five core security functions: Identify risks and threats, Protect, Detect, Respond and Recover. In addition, the Company requires that its employees complete annual compliance training on cybersecurity and online habits.

The Company’s cybersecurity program is managed by a dedicated cybersecurity function reporting to the Chief Information Security Officer (“CISO”) who reports to the Chief Information Officer (“CIO”) and is responsible for the Company’s cybersecurity strategy, policies, standards, architecture and process. The CISO has over 20 years of executive experience in IT operations and security, primarily in the airline industry, and maintains several active certifications in Risk and Information Security including CIPPUS, CISSP-ISSMP, CISM, CRISC, and CISSP. The program includes periodic and ad hoc reporting on relevant developments, including monitoring, prevention, detection, mitigation and remediation of the current cybersecurity landscape as well as reporting on any cybersecurity incidents to the Company’s CEO and the Safety, Security and Operations Committee of the Board of Directors, which has oversight of management’s cybersecurity function. The CISO also engages external government and commercial expertise to continuously evaluate, test and adapt the program. External vendors participate in in-depth security assessments based on the Company’s vendor management security policy.
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block] The Company uses multiple layers of security controls and unique threat intelligence within the “Center for Internet Security v8 Cybersecurity Framework” across five core security functions: Identify risks and threats, Protect, Detect, Respond and Recover. In addition, the Company requires that its employees complete annual compliance training on cybersecurity and online habits.
Cybersecurity Risk Management Third Party Engaged [Flag] true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag] true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag] false
Cybersecurity Risk Board of Directors Oversight [Text Block] The program includes periodic and ad hoc reporting on relevant developments, including monitoring, prevention, detection, mitigation and remediation of the current cybersecurity landscape as well as reporting on any cybersecurity incidents to the Company’s CEO and the Safety, Security and Operations Committee of the Board of Directors, which has oversight of management’s cybersecurity function. The CISO also engages external government and commercial expertise to continuously evaluate, test and adapt the program. External vendors participate in in-depth security assessments based on the Company’s vendor management security policy.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block] The Company’s cybersecurity program is managed by a dedicated cybersecurity function reporting to the Chief Information Security Officer (“CISO”) who reports to the Chief Information Officer (“CIO”) and is responsible for the Company’s cybersecurity strategy, policies, standards, architecture and process.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] The program includes periodic and ad hoc reporting on relevant developments, including monitoring, prevention, detection, mitigation and remediation of the current cybersecurity landscape as well as reporting on any cybersecurity incidents to the Company’s CEO and the Safety, Security and Operations Committee of the Board of Directors, which has oversight of management’s cybersecurity function.
Cybersecurity Risk Role of Management [Text Block] The Company’s cybersecurity program is managed by a dedicated cybersecurity function reporting to the Chief Information Security Officer (“CISO”) who reports to the Chief Information Officer (“CIO”) and is responsible for the Company’s cybersecurity strategy, policies, standards, architecture and process.
Cybersecurity Risk Management Positions or Committees Responsible [Flag] true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block] The Company’s cybersecurity program is managed by a dedicated cybersecurity function reporting to the Chief Information Security Officer (“CISO”) who reports to the Chief Information Officer (“CIO”) and is responsible for the Company’s cybersecurity strategy, policies, standards, architecture and process.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block] The CISO has over 20 years of executive experience in IT operations and security, primarily in the airline industry, and maintains several active certifications in Risk and Information Security including CIPPUS, CISSP-ISSMP, CISM, CRISC, and CISSP.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block] The program includes periodic and ad hoc reporting on relevant developments, including monitoring, prevention, detection, mitigation and remediation of the current cybersecurity landscape as well as reporting on any cybersecurity incidents to the Company’s CEO and the Safety, Security and Operations Committee of the Board of Directors, which has oversight of management’s cybersecurity function.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] true
v3.25.0.1
Summary of Significant Accounting Policies (Policies)
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Basis of Presentation
Basis of Presentation
The accompanying consolidated financial statements include the accounts of Spirit Airlines, Inc. ("Spirit") and its consolidated subsidiaries (the "Company"). Spirit is headquartered in Dania Beach, Florida, offers affordable travel to value-conscious customers and serves destinations throughout the United States, Latin America and the Caribbean. Spirit manages operations on a system-wide basis due to the interdependence of its route structure in the various markets served.
The classification of certain prior year amounts have been adjusted on the Company's consolidated financial statements and these Notes to conform to current year classifications.
Use of Estimates
Use of Estimates
The preparation of financial statements in accordance with generally accepted accounting principles in the United States of America requires the Company's management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. The Company's estimates and assumptions are based on historical experience and changes in the business environment. However, actual results may differ from estimates under different conditions, sometimes materially.
Cash and Cash Equivalents, Restricted Cash
Cash and Cash Equivalents
The Company considers all highly liquid investments with maturities of less than three months at the date of acquisition to be cash equivalents. Investments included in this category primarily consist of cash and money market funds. Cash and cash equivalents are stated at cost, which approximates fair value.
Restricted Cash
The Company's restricted cash is comprised of cash held in an account subject to a control agreement to be used for the payment of interest and fees on the Company's 8.00% senior secured notes, cash held in an account subject to a control agreement under its credit card processing agreement, pledged cash pursuant to its corporate credit cards and cash pledged as collateral against the Company's standby letters of credit.
Short-term Investment Securities
Short-term Investment Securities
The Company's short-term investment securities are classified as available-for-sale and generally consist of U.S. Treasury and U.S. government agency securities with contractual maturities of twelve months or less. The Company's short-term investment securities are categorized as Level 1 instruments, as the Company uses quoted market prices in active markets when determining the fair value of these securities. For additional information, refer to Note 8, Short-term Investment Securities. These securities are stated at fair value within current assets on the Company's consolidated balance sheet. For all short-term investments, at each reset period or upon reinvestment, the Company accounts for the transaction as proceeds from the maturity of short-term investment securities for the security relinquished, and purchase of short-term investment securities for the security purchased, in the Company's consolidated statements of cash flows. Realized gains and losses on sales of investments, if any, are reflected in non-operating other (income) expense in the consolidated statements of operations. Unrealized gains and losses on investment securities are reflected as a component of accumulated other comprehensive income.
Accounts Receivable
Accounts Receivable
Accounts receivable primarily consist of amounts due from credit card processors associated with the sales of tickets, amounts due from the Internal Revenue Service related to federal excise fuel tax and amounts expected to be received related to the CARES Employee Retention credit. The Company records an allowance for amounts not expected to be collected. The Company estimates the allowance based on historical write-offs and aging trends as well as an estimate of the expected lifetime credit losses.
Property and Equipment
Property and Equipment
Property and equipment is stated at cost, less accumulated depreciation and amortization. Depreciation of operating property and equipment is computed using the straight-line method applied to each unit of property. Residual values for new aircraft, new engines, major spare rotable parts, avionics and assemblies are generally estimated to be 10%. Property under finance leases and related obligations are initially recorded at an amount equal to the present value of future minimum lease payments computed using the Company's incremental borrowing rate or, when known, the interest rate implicit in the lease. Amortization of property under finance leases is recorded on a straight-line basis over the lease term and is included in depreciation and amortization expense.
The depreciable lives used for the principal depreciable asset classifications are:
 Estimated Useful Life
Aircraft, engines and flight simulators
25
Spare rotables and flight assemblies
7 to 25 years
Other equipment and vehicles
5 to 7 years
Internal use software
3 to 10 years
Finance leasesLease term or estimated useful life of the asset
Leasehold improvementsLesser of lease term or estimated useful life of the improvement
Buildings
Lesser of lease term or 40 years
The Company capitalizes certain internal and external costs associated with the acquisition and development of internal-use software for new products, and enhancements to existing products, that have reached the application development stage and meet recoverability tests. Capitalized costs include external direct costs of materials and services utilized in developing or obtaining internal-use software, and labor cost for employees who are directly associated with, and devote time, to internal-use software projects. The Company accounts for heavy maintenance and major overhaul under the deferral method whereby the cost of heavy maintenance is capitalized and amortized as a component of depreciation and amortization expense in the consolidated statements of operations until the earlier of the next heavy maintenance event or the end of the lease term.
Operating Lease Right-of-Use Asset and Liabilities
Operating Lease Right-of-Use Asset and Liabilities
Right-of-use assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. When available, the Company uses the rate implicit in the lease to discount lease payments to present value. However, the Company's
leases generally do not provide a readily determinable implicit rate. Therefore, the Company estimates the incremental borrowing rate to discount lease payments based on information available at lease commencement. The Company uses publicly available data for instruments with similar characteristics when calculating its incremental borrowing rates. The Company has options to extend certain of its operating leases for an additional period of time and options to early terminate several of its operating leases. The lease term consists of the noncancellable period of the lease, periods covered by options to extend the lease if the Company is reasonably certain to exercise the option and periods covered by an option to terminate the lease if the Company is reasonably certain not to exercise the option. The Company's lease agreements do not contain any residual value guarantees. The Company elected to not separate non-lease components from the associated lease component for all underlying classes of assets with lease and non-lease components.
The Company elected not to apply the recognition requirements in Topic 842 to short-term leases (i.e., leases of 12 months or less) but instead recognize these lease payments in income on a straight-line basis over the lease term. The Company elected this accounting policy for all classes of underlying assets. In addition, in accordance with Topic 842, variable lease payments are not included in the recognition of a lease liability or right-of-use asset.
Pre-Delivery Deposits On Flight Equipment
Pre-Delivery Deposits on Flight Equipment
The Company is required to make pre-delivery deposit payments ("PDPs") towards the purchase price of each new aircraft and engine prior to the scheduled delivery date. These deposits are initially classified as pre-delivery deposits on flight equipment on the Company's consolidated balance sheets until the aircraft or engine is delivered, at which time the related PDPs are deducted from the final purchase price of the aircraft or engine and are reclassified to flight equipment on the Company's consolidated balance sheets. The Company may also be entitled to refunds of PDPs resulting from sale leaseback transactions for aircraft previously included in the Company’s order book, as well as any agreements that modify the timing of aircraft deliveries or involve the removal of aircraft from its order book. For additional information on transactions entered into by the Company in 2024 that provided PDP refunds, refer to Note 17, Commitments and Contingencies.
In addition, the Company capitalizes the interest that is attributable to the outstanding PDP balances as a percentage of the related debt on which interest is incurred. Capitalized interest represents interest cost incurred during the acquisition period of a long-term asset and is the amount which theoretically could have been avoided had the Company not paid PDPs for the related aircraft or engines.
Related interest is capitalized and included within pre-delivery deposits on flight equipment through the acquisition period until delivery is taken of the aircraft or engine and the asset is ready for service. Once the aircraft or engine is delivered, the capitalized interest is also reclassified into flight equipment on the Company's consolidated balance sheets along with the related PDPs as they are included in the cost of the aircraft or engine. Capitalized interest for 2024, 2023 and 2022 was primarily related to the interest incurred on long-term debt.
Measurement of Asset Impairments
Measurement of Asset Impairments
The Company records impairment charges on long-lived assets used in operations when events and circumstances indicate that the assets may be impaired, the undiscounted future cash flows estimated to be generated by those assets are less than the carrying amount of those assets, and the net book value of the assets exceeds their estimated fair value. Factors which could be indicators of impairment include but are not limited to (1) a decision to permanently remove flight equipment or other long-lived assets from operations, (2) significant changes in the estimated useful life, (3) significant changes in projected cash flows, (4) permanent and significant declines in related fair values and (5) changes to the regulatory environment. If an impairment indicator is identified, the Company conducts a recoverability analysis. In performing the analysis, the Company uses certain assumptions, including, but not limited to: (i) estimated fair value of the assets; and (ii) estimated, undiscounted future cash flows expected to be generated by these assets, which are based on additional assumptions such as asset utilization, length of service the asset will be used in the Company’s operations, and estimated salvage values. Depending on the results of the recoverability analysis, an impairment loss is measured as the difference between the asset's carrying value and its fair value.
The Company has determined that indicators of potential impairment, including negative cash flows and its bankruptcy filing during the fourth quarter of 2024, were present as of December 31, 2024. These indicators prompted the Company to perform a recoverability analysis on its assets to assess whether any impairment losses should be recognized. In estimating the undiscounted future cash flows, the Company uses certain assumptions, including, but not limited to, the estimated, undiscounted future cash flows expected to be generated by these assets, estimates of length of service the asset will be used in the Company’s operations and estimated salvage values. The Company assessed whether any impairment of its long-lived assets existed as of December 31, 2024 and has determined that the assets are recoverable. The Company’s assumptions about future conditions important to its assessment of potential impairment of its long-lived assets are subject to uncertainty, and the Company will continue to monitor these conditions in future periods as new information becomes available and will update its analyses accordingly.
During 2023, the Company did not recognize impairment-related charges.
During the fourth quarter of 2022, the Company made the decision to accelerate the retirement of 29 of its A319 aircraft, which were owned and unencumbered, as of December 31, 2022. In January 2023, the Company executed a purchase agreement to sell these aircraft over the next two years. The Company concluded that Management’s plan to early retire and ultimately sell these 29 A319 aircraft is an impairment indicator which required the Company to test the recoverability of the related asset group as of December 31, 2022. No impairment indicators existed and no charges were necessary under applicable accounting standards as of December 31, 2022, for the remaining flight equipment, which together represent one asset group.
The Company concluded that the net book value of this specific asset group of owned A319 aircraft was not recoverable as of December 31, 2022, due to changes to the estimated future cash flows primarily driven by the significant reductions to their remaining operating lives. As a result, during 2022, the Company recognized $333.7 million in impairment-related charges for the amount by which the carrying amount of this asset group, including the related net capitalized maintenance, exceeded its estimated fair value. During 2022, the impairment charges were recorded within special charges (credits) in the Company’s consolidated statement of operations. The fair values of these assets were determined using Level 3 fair value inputs primarily based on the agreed upon sales price for each aircraft, adjusted for estimated utilization in the period of operation from December 31, 2022 to the expected future sales date. For additional information, refer to Note 5, Loss (Gain) on Disposal of Assets.
Revenues
Passenger Revenues

Operating revenues are comprised of passenger revenues and other revenues. Passenger revenues are primarily comprised of fares and related ancillary items such as bags, seats and other travel-related fees. Other revenues primarily consist of the marketing component of the sale of loyalty points to the Company's credit card partner and commissions revenue from the sale of various items, such as hotels and rental cars.
Passenger revenues are generally recognized once the related flight departs. Accordingly, the value of tickets and ancillary products sold in advance of travel is included under the Company's current liabilities as “air traffic liability,” or “ATL”, until the related air travel is provided. As of December 31, 2024 and December 31, 2023, the Company had ATL balances of $436.8 million and $383.8 million, respectively. Substantially all of the Company's ATL as of December 31, 2024 is expected to be recognized within 12 months of the respective balance sheet date.    
Changes and cancellations. An unused ticket expires at the date of scheduled travel, at which time a service charge is assessed, and is recognized as revenue at the date of scheduled travel. However, customers may elect to change or cancel their itinerary prior to the date of departure. In 2024, the Company launched its no change or cancel fee policy for its bundled travel
options. Guests are required to pay the difference in fare if the new trip is more expensive or receive a credit if the new trip is less expensive.

Any unused amount is placed in a credit shell which generally expires 12 months from the date the credit shell is created. Prior to May 2024, credit shells generally expired 90 days from the date the credit shell was created. Credit shells can be used towards the purchase of a new ticket and the Company’s other service offerings. Credit shell amounts are recorded as deferred revenue and amounts expected to expire unused are estimated based on historical experience.

Estimating the amount of credits that will go unused involves some level of subjectivity and judgment. Assumptions used to generate breakage estimates can be impacted by several factors including, but not limited to, changes to the Company's ticketing policies, changes to the Company’s refund, exchange, and credit shell policies, and economic factors. The amount of credit shells issued varies, primarily due to the flight delays and cancellation events throughout the year. The Company generally experiences some variability in the amount of breakage revenue recognized throughout the year and expects some variability in the amount of breakage revenue recorded in future periods, as the estimates of the portion of those funds that will expire unused may differ from historical experience.

Loyalty Program
    
The Company operates the Spirit Saver$ Club®, which is a subscription-based loyalty program that allows members access to exclusive, extra-low fares, as well as discounted prices on bags and seats, shortcut boarding and security, and exclusive offers on hotels, rental cars and other travel necessities. The Company also operates the Free Spirit loyalty program (the "Free Spirit Program"), which attracts members and partners and builds customer loyalty for the Company by offering a variety of awards, benefits and services. Free Spirit loyalty program members earn and accrue points for dollars spent on Spirit for flights and other non-fare services, as well as services from non-air partners such as retail merchants, hotels or car rental companies. Customers can also earn points based on their spending with the Company's co-branded credit card company with which the Company has an agreement to sell points. The Company's co-branded credit card agreement provides for joint marketing pursuant to which cardholders earn points by making purchases using co-branded cards. Points earned and accrued by Free Spirit loyalty program members can be redeemed for travel awards such as free (other than taxes and government-imposed fees), discounted or upgraded travel. The Company's agreement with the administrator of the Free Spirit affinity credit card program expires on December 31, 2028.
The Company defers the amount of award travel obligations as part of loyalty deferred revenue within ATL on the Company's consolidated balance sheets and recognizes loyalty travel awards in passenger revenues as points are used for travel or expire unused.

    To reflect the point credits earned, the program includes two types of transactions that are considered revenue arrangements with multiple performance obligations: (1) points earned with travel and (2) points sold to its co-branded credit card partner.

    Passenger ticket sales earning points. Passenger ticket sales earning points provide customers with (1) points earned and (2) air transportation. The Company values each performance obligation on a stand-alone basis and allocates the consideration to each performance obligation based on their relative fair value. To value the point credits earned, the Company considers the quantitative value a passenger receives by redeeming points for a ticket rather than paying cash, which is referred to as equivalent ticket value ("ETV").

The Company defers revenue for the points when earned and recognizes loyalty travel awards in passenger revenue as the points are redeemed and services are provided. The Company records the air transportation portion of the passenger ticket sales in air traffic liability and recognizes passenger revenue when transportation is provided or if the ticket goes unused, at the date of scheduled travel.

    Sale of points. Customers may earn points based on their spending with the Company's co-branded credit card company with which the Company has an agreement to sell points. The contract to sell points under this agreement has multiple performance obligations, as discussed below.

The Company's co-branded credit card agreement provides for joint marketing where cardholders earn points for making purchases using co-branded cards. During 2023, the Company extended its agreement with the administrator of the Free Spirit affinity credit card program through December 31, 2028. The Company accounts for this agreement consistently with the accounting method that allocates the consideration received to the individual products and services delivered. The value is
allocated based on the relative stand-alone selling prices of those products and services, which generally consists of (i) points to be awarded, (ii) airline benefits, collectively referred to as the "award travel components," (iii) licensing of brand and access to member lists and (iv) advertising and marketing efforts, collectively referred to as the "marketing components." Revenue allocated to the award travel components are recorded in passenger revenues, while the revenue allocated to the marketing components are recorded in other revenues. The Company determined the estimate of the stand-alone selling prices by considering discounted cash flow analysis using multiple inputs and assumptions, including: (1) the expected number of points awarded and number of points redeemed, (2) the estimated stand-alone selling price of the award travel obligation and airline benefits, (3) licensing of brand access to member lists and (4) the cost of advertising and marketing efforts undertaken by the Company.

The Company defers the amount for award travel obligation as part of loyalty deferred revenue. These amounts that are expected to be redeemed during the following twelve months are recorded within ATL on the Company's consolidated balance sheet and the portion that is expected to be redeemed beyond the following twelve months is recorded within long-term liabilities on the consolidated balance sheet. In addition, the Company recognizes loyalty travel awards in passenger revenue as the points are used for travel. Revenue allocated to the marketing components are recorded in other revenue as points are delivered. Total unrecognized revenue from future Free Spirit Program was $101.5 million and $104.6 million at December 31, 2024 and 2023, respectively. The current portion of this balance is recorded within air traffic liability and the long-term portion of this balance is recorded within deferred gains and other long-term liabilities in the accompanying consolidated balance sheets.
Points breakage. For points that the Company estimates are not likely to be redeemed ("breakage"), the Company recognizes the associated value proportionally during the period in which the remaining points are redeemed. Management uses statistical models to estimate breakage based on historical redemption patterns. A change in assumptions as to the period over which points are expected to be redeemed, the actual redemption activity for points or the estimated fair value of points expected to be redeemed could have an impact on revenues in the year in which the change occurs and in future years.
    Current activity of loyalty program. Points are combined in one homogeneous pool and are not separately identifiable. As such, revenue is composed of points that were part of the loyalty deferred revenue balance at the beginning of the period as well as points that were issued during the period.

Other Revenues

Other revenues primarily consist of the marketing component of the sale of loyalty points to the Company's credit card partner and commissions revenue from the sale of various items such as hotels and rental cars.
Airframe and Engine Maintenance
Airframe and Engine Maintenance
The Company accounts for heavy maintenance and major overhaul under the deferral method whereby the cost of heavy maintenance and major overhaul is deferred and amortized until the earlier of the end of the useful life of the related asset, the end of the remaining lease term or the next scheduled heavy maintenance event.
The Company outsources certain routine, non-heavy maintenance functions under contracts that require payment on a utilization basis, primarily based on flight hours. Costs incurred for maintenance and repair under flight hour maintenance contracts, where labor and materials price risks have been transferred to the service provider, are expensed based on contractual payment terms. All other costs for routine maintenance of the airframes and engines are charged to expense as performed.
Leased Aircraft Return Costs
Leased Aircraft Return Costs
The Company's aircraft lease agreements often contain provisions that require the Company to return aircraft airframes, engines and other aircraft components to the lessor in a certain condition or pay an amount to the lessor based on the airframe and engine's actual return condition. Lease return costs include all costs that would be incurred at the return of the aircraft, including costs incurred to repair the airframe and engines to the required condition as stipulated by the lease. Lease return costs are recognized beginning when it is probable that such costs will be incurred and they can be estimated.
When determining the probability to accrue lease return costs, there are various estimated costs and factors which need to be considered such as the contractual terms of the lease agreement, current condition of the aircraft, the age of the aircraft at lease expiration, projected number of hours run on the engine at the time of return, and the number of projected cycles run on the airframe at the time of return, among others. Management assesses the need to accrue lease return costs periodically throughout the year or whenever facts and circumstances warrant an assessment. Lease return costs will generally be estimable closer to the end of the lease term but may be estimable earlier in the lease term depending on the contractual terms of the lease agreement and the timing of maintenance events for a particular aircraft.
Aircraft Fuel
Aircraft Fuel
Aircraft fuel expense includes jet fuel and associated into-plane costs, taxes, and oil, and realized and unrealized gains and losses associated with fuel derivative contracts, if any.
Advertising
Advertising
The Company expenses advertising and the production costs of advertising as incurred.
Income Taxes
Income Taxes
The Company accounts for income taxes using the asset and liability method. The Company records a valuation allowance to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that some portion or all of the deferred tax assets will be not realized.
Stock-Based Compensation
Stock-Based Compensation
The Company recognizes cost of employee services received in exchange for awards of equity instruments based on the fair value of each instrument at the date of grant. For the majority of awards, compensation expense is recognized on a straight-line basis over the period during which an employee is required to provide service in exchange for an award. Certain awards have performance conditions that must be achieved prior to vesting and are expensed based on the expected achievement at each reporting period. The Company has issued restricted stock awards, performance share award and performance and market share awards. Restricted stock awards are valued at the fair value of the shares on the date of grant. The fair value of performance share awards based on a market condition are estimated through the use of a Monte Carlo simulation model. The fair value of performance share awards based on a performance condition is based on the fair value of the shares on the date of grant. The performance share awards based on a performance condition are evaluated at each report date and adjustments are made to stock-based compensation expense based on the number of shares deemed probable of issuance upon vesting. The fair value of the market and performance share awards are estimated through the use of a Monte Carlo simulation model and adjusted based on the number of shares deemed probable of issuance upon vesting.
Concentrations of Risk
Concentrations of Risk
Aircraft Fuel. The Company’s business may be adversely affected by increases in the price of aircraft fuel, the volatility of the price of aircraft fuel, or both. Aircraft fuel, one of the Company’s largest expenditures, represented approximately 25%, 31% and 34% of total operating expenses in 2024, 2023 and 2022, respectively.
The Company’s operations are largely concentrated in the southeast United States with Fort Lauderdale being the highest volume fueling point in the system. Gulf Coast Jet indexed fuel is the basis for a substantial majority of the Company’s fuel consumption. Any disruption to the oil production or refinery capacity in the Gulf Coast, as a result of weather or any other disaster, or disruptions in supply of jet fuel, dramatic escalations in the costs of jet fuel and/or the failure of fuel providers to perform under fuel arrangements for other reasons could have a material adverse effect on the Company’s financial condition and results of operations.
Weather Conditions. The Company’s operations will continue to be vulnerable to weather conditions (including hurricane season or snow and severe winter weather), which could disrupt service or create air traffic control problems. These events may result in decreased revenue and/or increased costs.
Limited number of vendors. The Company relies on a limited number of vendors for the delivery of additional aircraft and engines - currently Airbus A320-family, single-aisle aircraft, powered by engines manufactured by IAE and Pratt & Whitney. Due to the relatively small size of the Company's fleet and high utilization rate, the unavailability of aircraft and engines, as well as the reduced capacity, resulting from delivery delays or performance issues from these vendors, could have a material adverse effect on the Company’s business, results of operations and financial condition.
Employees. As of December 31, 2024, the Company had six union-represented employee groups that together represented approximately 84% of all employees. A strike or other significant labor dispute with the Company’s unionized employees is likely to adversely affect the Company’s ability to conduct business.
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements Not Yet Adopted
Recently Adopted Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This standard improves reportable segment disclosure requirements by expanding annual and interim disclosure requirements for reportable segments, providing new segment disclosure requirements for entities with a single reportable segment, and adding other disclosure requirements. This standard is effective for the Company for fiscal years beginning January 1, 2024 and for interim periods beginning January 1, 2025. The Company adopted this standard effective January 1, 2024 with no impact to its consolidated financial statements. Refer to Note 19, Operating Segments and Related Disclosures for additional information.

Recently Issued Accounting Pronouncements Not Yet Adopted

In December 2023, the FASB issued ASU No. 2023-09 (“ASU 2023-09”), Income Taxes (Topic 740): Improvement to Income Tax Disclosures to enhance the transparency and decision usefulness of income tax disclosures. This standard is effective for the Company for fiscal years, and interim periods within those years, beginning January 1, 2025 on a prospective basis. Early adoption is permitted. The Company is currently evaluating the impact of this new standard.
In November 2024, the FASB issued ASU No. 2024-03 (“ASU 2024-03”), Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40). This standard requires disclosure of specific information about costs and expenses. This standard is effective for the Company for fiscal years, and interim periods within those years, beginning January 1, 2027 on a prospective basis. Early adoption is permitted. The Company is currently evaluating the impact of this new standard.
v3.25.0.1
Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Schedule of Depreciable Lives Used for the Principal Depreciable Asset Classifications and Components of Depreciation and Amortization
The depreciable lives used for the principal depreciable asset classifications are:
 Estimated Useful Life
Aircraft, engines and flight simulators
25
Spare rotables and flight assemblies
7 to 25 years
Other equipment and vehicles
5 to 7 years
Internal use software
3 to 10 years
Finance leasesLease term or estimated useful life of the asset
Leasehold improvementsLesser of lease term or estimated useful life of the improvement
Buildings
Lesser of lease term or 40 years
The following table illustrates the components of depreciation and amortization expense:
 Year Ended December 31,
202420232022
(in thousands)
Depreciation$177,872 $218,106 $199,118 
Amortization of heavy maintenance113,522 79,768 96,707 
Amortization of capitalized software33,879 22,998 17,265 
Total depreciation and amortization$325,273 $320,872 $313,090 
Schedule of Total Cash Proceeds Received from the Sale of Mileage Credit The following table illustrates total cash proceeds received from the sale of points and the portion of such proceeds recognized in passenger revenue immediately as marketing component:
Consideration received from credit card loyalty programsPortion of proceeds recognized immediately as marketing component
Year Ended(in thousands)
December 31, 2024$85,812 $51,220 
December 31, 202393,147 48,071 
December 31, 202280,970 40,987 
Schedule of Aircraft Maintenance Expense
The table below summarizes the components of the Company’s maintenance cost:
 Year Ended December 31,
202420232022
(in thousands)
Utilization-based maintenance expense$103,232 $117,458 $97,930 
Non-utilization-based maintenance expense114,506 105,881 89,890 
Total maintenance, materials and repairs$217,738 $223,339 $187,820 
v3.25.0.1
Chapter 11 Proceedings (Tables)
 12 Months Ended
Dec. 31, 2024
Reorganizations [Abstract]  
Schedule of Liabilities Subject to Compromise At December 31, 2024, “liabilities subject to compromise” of $1.6 billion consisted of the notes listed below as of the Petition Date:
December 31, 2024
(in millions)
8.00% senior secured notes due in 2025
$1,110.0 
Convertible notes due in 2025$25.1 
Convertible notes due in 2026500.0 
Liabilities subject to compromise$1,635.1 
Schedule of Reorganization,Expenses For the twelve months ended December 31, 2024, the Company recorded $96.8 million of reorganization expense which consisted of the following items:
December 31, 2024
(in millions)
Backstop premium(1)
$35.0 
Unamortized debt discounts (2)
20.7
Unamortized debt issuance costs (2)
9.0
DIP term loan financing fees12.6
Legal, consulting and other fees19.5
Total reorganization expense$96.8 

(1)    Refer to “Backstop Commitment Agreement” section above for additional information.
(2) Includes the unamortized discount as of the Petition Date related to the Company's 8.00% senior secured notes and convertible notes due 2025, as well as the unamortized debt issuance costs as of the Petition Date related to the Company's 8.00% senior secured notes, convertible notes due 2025 and convertible notes due 2026.
v3.25.0.1
Other Current Liabilities (Tables)
 12 Months Ended
Dec. 31, 2024
Payables and Accruals [Abstract]  
Schedule of Other Current Liabilities
Accrued liabilities included in other current liabilities as of December 31, 2024 and 2023 consist of the following:

 As of December 31,
20242023
(in thousands)
Salaries, wages and benefits$187,626 $187,723 
Federal excise and other passenger taxes and fees payable110,141 104,447 
Aircraft maintenance103,133 58,800 
Airport obligations66,518 125,278 
Backstop premium obligation35,000 — 
Interest payable26,780 24,732 
Aircraft and facility lease obligations23,926 36,115 
Fuel5,202 64,149 
Other47,513 104,054 
Other current liabilities$605,839 $705,298 
v3.25.0.1
Stock-Based Compensation (Tables)
 12 Months Ended
Dec. 31, 2024
Share-Based Payment Arrangement [Abstract]  
Schedule of the Status of the Company's Restricted Stock Unit Awards
A summary of the status of the Company’s restricted stock unit awards (restricted stock awards and restricted stock unit awards) as of December 31, 2024 and changes during the year ended December 31, 2024 is presented below:
Number of SharesWeighted-Average
Grant Date Fair Value ($)
Outstanding at December 31, 2023705,888 20.93 
Granted1,140,060 5.81 
Vested(336,867)20.61 
Forfeited(193,185)12.86 
Outstanding at December 31, 20241,315,896 9.10 
v3.25.0.1
Earnings (Loss) per Share (Tables)
 12 Months Ended
Dec. 31, 2024
Earnings Per Share [Abstract]  
Schedule of Computation of Basic and Diluted Earnings (Loss) Per Common Share
The following table sets forth the computation of basic and diluted earnings (loss) per common share:

 Year Ended December 31,
202420232022
 (in thousands, except per-share amounts)
Numerator:
Net income (loss)$(1,229,495)$(447,464)$(554,150)
Denominator:
Weighted-average shares outstanding, basic109,495 109,152 108,751 
Effect of dilutive stock awards— — — 
Adjusted weighted-average shares outstanding, diluted109,495 109,152 108,751 
Earnings (loss) per share:
Basic earnings (loss) per common share $(11.23)$(4.10)$(5.10)
Diluted earnings (loss) per common share$(11.23)$(4.10)$(5.10)
v3.25.0.1
Debt and Other Obligations (Tables)
 12 Months Ended
Dec. 31, 2024
Debt Disclosure [Abstract]  
Schedule of Long-term Debt Instruments
Long-term debt is comprised of the following:
As of
December 31, 2024December 31, 2023December 31, 2024December 31, 2023
(in millions)(weighted-average interest rates)
DIP term loan due in 2025$309.0 $— 11.82 %N/A
8.00% senior secured notes due in 2025 (2)
— 1,110.0 8.00 %8.00 %
Fixed-rate term loans due through 2039 (1)
972.2 1,093.3 6.44 %5.83 %
Unsecured term loans due through 2031136.3 136.3 1.00 %1.00 %
Fixed-rate class A 2015-1 EETC due through 2028
234.6 256.6 4.10 %4.10 %
Fixed-rate class B 2015-1 EETC due through 2024
— 40.0 4.45 %4.45 %
Fixed-rate class AA 2017-1 EETC due through 2030
160.3 172.2 3.38 %3.38 %
Fixed-rate class A 2017-1 EETC due through 2030
53.4 57.4 3.65 %3.65 %
Fixed-rate class B 2017-1 EETC due through 2026
44.7 48.2 3.80 %3.80 %
Convertible notes due in 2025 (2)
— 25.1 4.75 %4.75 %
Convertible notes due in 2026 (2)
— 500.0 1.00 %1.00 %
Revolving credit facility due in 2026300.0 — 6.67 %N/A
Long-term debt$2,210.5 $3,439.1 
Less current maturities436.3 315.3 
Less unamortized discount, net
13.2 69.0 
Total$1,761.0 $3,054.8 

(1) Includes obligations related to 18 aircraft recorded as failed sale leaseback transactions. Refer to Note 14, Leases for additional information.
(2) As of December 31, 2024, these debt instruments are recorded within liabilities subject to compromise on the Company's consolidated balance sheets. Refer to Note 3, Chapter 11 Proceedings, for additional information.
Schedule of Maturities of Long-term Debt
At December 31, 2024, long-term debt principal payments for the next five years and thereafter are as follows:
December 31, 2024
(in millions)
2025$415.2 
2026429.1 
2027192.9 
2028257.2 
202984.8 
2030 and beyond831.3 
Total debt principal payments$2,210.5 
Schedule of Interest Expense on Long-term Debt and Capital Leases
Interest expense related to long-term debt and finance leases consists of the following:
 Twelve Months Ended December 31,
202420232022
(in thousands)
8.00% senior secured notes (1)
$92,621 $93,010 $47,954 
Fixed-rate term loans69,635 37,213 41,446 
Unsecured term loans1,365 1,363 1,363 
Class A 2015-1 EETC10,078 10,962 11,874 
Class B 2015-1 EETC446 1,954 2,312 
Class C 2015-1 EETC— 777 3,424 
Class AA 2017-1 EETC5,561 5,990 6,464 
Class A 2017-1 EETC2,005 2,159 2,330 
Class B 2017-1 EETC1,748 1,881 2,016 
Class C 2017-1 EETC— 522 4,367 
Convertible notes (2)
15,849 (3,778)(68)
Revolving credit facility4,501 — — 
DIP term loan812 — — 
Finance leases33 30 57 
Commitment and other fees1,340 1,655 2,162 
Amortization of deferred financing costs13,100 15,453 14,204 
Total$219,094 $169,191 $139,905 
(1) Includes $3.8 million, $4.2 million and $1.4 million of accretion and $88.8 million, $88.8 million and $46.5 million of interest expense for the twelve months ended December 31, 2024, 2023, and 2022, respectively.
(2) Includes $16.4 million, $14.3 million and $20.3 million of amortization of the discount for the convertible notes due 2026 as well as interest expense for the convertible notes due 2025 and 2026, offset by $0.5 million, $18.1 million and $20.3 million of favorable mark to market adjustments for the convertible notes due 2026 for the twelve months ended December 31, 2024, 2023, and 2022, respectively.
v3.25.0.1
Leases (Tables)
 12 Months Ended
Dec. 31, 2024
Leases [Abstract]  
Schedule of Future Minimum Lease Payments for Finance Leases
The following table provides details of the Company's future minimum lease payments under finance lease liabilities and operating lease liabilities recorded on the Company's consolidated balance sheets as of December 31, 2024. The table does not include commitments that are contingent on events or other factors that are currently uncertain and unknown.
Finance LeasesOperating LeasesTotal Operating and Finance Lease Obligations
Aircraft and Spare Engine LeasesProperty Facility Leases
(in thousands)
2025$219 $564,040 $5,047 $569,306 
2026141 538,911 4,939 543,991 
202793 522,951 4,140 527,184 
202867 502,185 2,757 505,009 
20296 486,881 2,129 489,016 
2030 and thereafter— 4,842,905 141,638 4,984,543 
Total minimum lease payments$526 $7,457,873 $160,650 $7,619,049 
Less amount representing interest50 2,893,031 132,590 3,025,671 
Present value of minimum lease payments$476 $4,564,842 $28,060 $4,593,378 
Less current portion195 254,521 3,275 257,991 
Long-term portion$281 $4,310,321 $24,785 $4,335,387 
Schedule of Future Minimum Lease Payments for Operating Leases
The following table provides details of the Company's future minimum lease payments under finance lease liabilities and operating lease liabilities recorded on the Company's consolidated balance sheets as of December 31, 2024. The table does not include commitments that are contingent on events or other factors that are currently uncertain and unknown.
Finance LeasesOperating LeasesTotal Operating and Finance Lease Obligations
Aircraft and Spare Engine LeasesProperty Facility Leases
(in thousands)
2025$219 $564,040 $5,047 $569,306 
2026141 538,911 4,939 543,991 
202793 522,951 4,140 527,184 
202867 502,185 2,757 505,009 
20296 486,881 2,129 489,016 
2030 and thereafter— 4,842,905 141,638 4,984,543 
Total minimum lease payments$526 $7,457,873 $160,650 $7,619,049 
Less amount representing interest50 2,893,031 132,590 3,025,671 
Present value of minimum lease payments$476 $4,564,842 $28,060 $4,593,378 
Less current portion195 254,521 3,275 257,991 
Long-term portion$281 $4,310,321 $24,785 $4,335,387 
Schedule of Lease Costs, Lease Terms and Discount Rates
The table below presents information for lease costs related to the Company's finance and operating leases:
Year Ended December 31,
20242023
(in thousands)
Finance lease cost
Amortization of leased assets$277 $451 
Interest of lease liabilities33 30 
Operating lease cost
Operating lease cost (1)
517,016 377,505 
Short-term lease cost (1)
37,294 39,916 
Variable lease cost (1)
272,087 227,030 
Total lease cost$826,707 $644,932 
(1) Expenses are classified within aircraft rent and landing fees and other rents on the Company's consolidated statements of operations.
The table below presents lease-related terms and discount rates as of December 31, 2024:
December 31, 2024December 31, 2023
Weighted-average remaining lease term
Operating leases15.1 years14.8 years
Finance leases2.9 years2.3 years
Weighted-average discount rate
Operating leases7.11 %6.84 %
Finance leases5.91 %4.25 %
v3.25.0.1
Income Taxes (Tables)
 12 Months Ended
Dec. 31, 2024
Income Tax Disclosure [Abstract]  
Schedule of Significant Components of the Provision for Income Taxes from Continuing Operations
Significant components of the provision for income taxes from continuing operations are as follows:
 Year Ended December 31,
202420232022
(in thousands)
Current:
Federal$(5,438)$5,449 $— 
State and local(40)1,309 327 
Foreign3,485 1,350 1,695 
Total current expense (benefit)(1,993)8,108 2,022 
Deferred:
Federal(54,922)(115,905)(141,251)
State and local(3,293)(3,334)(7,360)
Total deferred expense (benefit)(58,215)(119,239)(148,611)
Total income tax expense (benefit)$(60,208)$(111,131)$(146,589)
Schedule of Reconciliation of Income Tax Expense
The income tax provision differs from that computed at the federal statutory corporate tax rate as follows:
 Year Ended December 31,
202420232022
Expected provision at federal statutory tax rate21.0 %21.0 %21.0 %
State tax expense, net of federal benefit1.3 %1.5 %1.6 %
Permanent tax differences(1.6)%(1.3)%(0.6)%
Valuation allowance(16.1)%(1.2)%(0.8)%
Other0.1 %(0.1)%(0.3)%
Total income tax expense (benefit)4.7 %19.9 %20.9 %
Schedule of Deferred Taxes At December 31, 2024 and 2023, the significant components of the Company's deferred taxes consisted of the following:
 December 31,
20242023
(in thousands)
Deferred tax assets:
Income tax credits$2,441 $4,298 
Net operating losses437,400 328,977 
Deferred revenue22,641 25,924 
Nondeductible accruals29,936 32,899 
Deferred manufacturing credits13,415 14,556 
Loan liability140,313 115,161 
Operating lease liability1,053,684 797,778 
Interest expense70,011 51,305 
Other17,496 38,910 
Valuation allowance(226,389)(17,654)
Deferred tax assets1,560,948 $1,392,154 
Deferred tax liabilities:
Property, plant and equipment513,028 612,571 
Accrued aircraft and engine maintenance54,574 70,997 
Right-of-use asset1,042,099 803,232 
Other3,174 13,115 
Deferred tax liabilities1,612,875 1,499,915 
Net deferred tax assets (liabilities)$(51,927)$(107,761)
v3.25.0.1
Commitments and Contingencies (Tables)
 12 Months Ended
Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]  
Schedules of Concentration of Risk, by Risk Factor The table below sets forth the Company's employee groups and status of the CBAs.
Employee Groups  Representative  
Amendable Date (1)
Percentage of Workforce
Pilots  
Air Line Pilots Association, International (ALPA) (2)
  March 202427%
Flight Attendants  Association of Flight Attendants (AFA-CWA)  January 202644%
Dispatchers  Professional Airline Flight Control Association (PAFCA)  August 20261%
Ramp Service AgentsInternational Association of Machinists and Aerospace Workers (IAMAW)November 20263%
Passenger Service AgentsTransport Workers Union of America (TWU)February 20273%
Aircraft Maintenance Technicians
Aircraft Mechanics Fraternal Association (AMFA) (2)
N/A 6%

(1) Subject to standard early opener provisions.
(2) Collective bargaining agreement is currently under negotiation.
v3.25.0.1
Fair Value Measurements (Tables)
 12 Months Ended
Dec. 31, 2024
Fair Value Disclosures [Abstract]  
Schedule of Long-Term Debt Measured at Fair Value The carrying amounts and estimated fair values of the Company's long-term debt at December 31, 2024 and December 31, 2023, were as follows:
As of December 31,
20242023
 Carrying ValueEstimated Fair ValueCarrying ValueEstimated Fair ValueFair value level hierarchy
(in millions)
DIP term loans$309.0 $309.0 $— $— Level 3
Fixed-rate term loans972.2 970.7 1,093.3 1,099.9 Level 3
Unsecured term loans136.3 130.4 136.3 128.3 Level 3
2015-1 EETC Class A 234.6 215.8 256.6 230.8 Level 2
2015-1 EETC Class B — — 40.0 39.4 Level 2
2017-1 EETC Class AA160.3 140.4 172.2 149.6 Level 2
2017-1 EETC Class A53.4 45.8 57.4 48.5 Level 2
2017-1 EETC Class B44.7 40.5 48.2 42.9 Level 2
Revolving credit facility due 2026300.0 300.0 — — Level 3
Total long-term debt$2,210.5 $2,152.6 $1,804.0 $1,739.4 
8.00% senior secured notes
$1,110.0 $1,117.9 $1,110.0 $1,121.9 Level 3
4.75% convertible notes due 2025
25.1 8.8 25.1 42.3 Level 2
1.00% convertible notes due 2026
500.0 166.4 500.0 349.9 Level 2
Total liabilities subject to compromise$1,635.1 $1,293.1 $1,635.1 $1,514.1 
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets and liabilities measured at gross fair value on a recurring basis are summarized below:
 
 Fair Value Measurements as of December 31, 2024
 TotalLevel
1		Level
2		Level
3
(in millions)
Cash and cash equivalents$902.1 $902.1 $— $— 
Restricted cash168.4 168.4 — — 
Short-term investment securities118.3 118.3 — — 
Assets held for sale463.0 — — 463.0 
Total assets$1,651.8 $1,188.8 $— $463.0 
Total liabilities$— $— $— $— 
 
 Fair Value Measurements as of December 31, 2023
 TotalLevel
1		Level
2		Level
3
(in millions)
Cash and cash equivalents$865.2 $865.2 $— $— 
Restricted cash119.4 119.4 — — 
Short-term investment securities112.5 112.5 — — 
Assets held for sale1.8 — — 1.8 
Total assets$1,098.9 $1,097.1 $— $1.8 
Derivative liability$11.1 $— $11.1 $— 
Total liabilities$11.1 $— $11.1 $— 
v3.25.0.1
Operating Segments and Related Disclosures (Tables)
 12 Months Ended
Dec. 31, 2024
Segment Reporting [Abstract]  
Schedule of Operating Revenues by Geographic Region Operating revenues by geographic region as defined by the Department of Transportation ("DOT") area are summarized below:
202420232022
(in millions)
DOT—Domestic$4,358.2 $4,676.1 $4,371.8 
DOT—Latin America and Caribbean555.2 686.4 696.6 
Total$4,913.4 $5,362.5 $5,068.4 
v3.25.0.1
Summary of Significant Accounting Policies - Narrative (Details)
Dec. 31, 2024
Nov. 18, 2024
8.00% senior secured notes | 8.00% senior secured notes due in 2025    
Debt Instrument [Line Items]    
Stated interest rate percentage 8.00% 8.00%
v3.25.0.1
Summary of Significant Accounting Policies - Property and Equipment (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
USD ($)
aircraft
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2024
Dec. 31, 2024
aircraft
Dec. 31, 2024
aircraftLeasebackTransaction
Dec. 31, 2024
aircraft_engine
Dec. 31, 2024
flightSimulator
Dec. 31, 2024
a
Dec. 31, 2019
USD ($)
a
residential_building_unit
Property, Plant and Equipment [Line Items]                      
Number of aircraft recorded as asstes held for sale | aircraft 21                    
Number of spare engines capitalized | aircraft_engine               32      
Number of flight simulators capitalized | flightSimulator                 4    
Area of land | a                   8.5 8.5
Land                     $ 41,000
Depreciation, Depletion and Amortization, Nonproduction [Abstract]                      
Depreciation $ 177,872 $ 218,106 $ 199,118                
Amortization of capitalized software 33,879 22,998 17,265                
Total depreciation and amortization $ 325,273 320,872 313,090                
Deferred heavy maintenance, net   313,505   $ 241,094              
Other                      
Property, Plant and Equipment [Line Items]                      
Area of land | a                     2.6
Number of residential building unit expected to be built | residential_building_unit                     200
Minimum | Aircraft                      
Property, Plant and Equipment [Line Items]                      
Operating lease contract term 4 years                    
Maximum | Aircraft                      
Property, Plant and Equipment [Line Items]                      
Operating lease contract term 18 years                    
Maximum | Other                      
Property, Plant and Equipment [Line Items]                      
Operating lease contract term 99 years                   99 years
Aircrafts, Major Spare Rotable Parts, Avionics, and Assemblies                      
Property, Plant and Equipment [Line Items]                      
Residual value, percentage         10.00%            
Aircraft, engines and flight simulators                      
Property, Plant and Equipment [Line Items]                      
Depreciable lives used for the principal depreciable asset classifications 25 years                    
Spare rotables and flight assemblies | Minimum                      
Property, Plant and Equipment [Line Items]                      
Depreciable lives used for the principal depreciable asset classifications 7 years                    
Spare rotables and flight assemblies | Maximum                      
Property, Plant and Equipment [Line Items]                      
Depreciable lives used for the principal depreciable asset classifications 25 years                    
Other equipment and vehicles | Minimum                      
Property, Plant and Equipment [Line Items]                      
Depreciable lives used for the principal depreciable asset classifications 5 years                    
Other equipment and vehicles | Maximum                      
Property, Plant and Equipment [Line Items]                      
Depreciable lives used for the principal depreciable asset classifications 7 years                    
Internal use software                      
Depreciation, Depletion and Amortization, Nonproduction [Abstract]                      
Capitalized computer software, net   53,600   $ 48,800              
Capitalized software costs during the year $ 29,200 35,500 25,700                
Internal use software | Minimum                      
Property, Plant and Equipment [Line Items]                      
Depreciable lives used for the principal depreciable asset classifications 3 years                    
Internal use software | Maximum                      
Property, Plant and Equipment [Line Items]                      
Depreciable lives used for the principal depreciable asset classifications 10 years                    
Buildings                      
Property, Plant and Equipment [Line Items]                      
Depreciable lives used for the principal depreciable asset classifications 40 years                    
Aircraft                      
Property, Plant and Equipment [Line Items]                      
Failed aircraft sale leaseback           18 18        
Aircraft | A320 Family                      
Property, Plant and Equipment [Line Items]                      
Number of aircraft capitalized | aircraft           46          
Heavy maintenance and major overhaul                      
Depreciation, Depletion and Amortization, Nonproduction [Abstract]                      
Amortization of heavy maintenance $ 113,522 $ 79,768 $ 96,707                
v3.25.0.1
Summary of Significant Accounting Policies - Assets Held for Sale (Details)
 3 Months Ended 12 Months Ended
Oct. 29, 2024
aircraft
Dec. 31, 2024
USD ($)
aircraft
Dec. 31, 2024
USD ($)
aircraft
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Property, Plant and Equipment [Line Items]          
Assets held for sale | $   $ 463,020,000 $ 463,020,000 $ 1,847,000  
Number of aircraft to be sold, held-for-sale | aircraft     21    
Fixed asset impairment charges | $     $ 0 $ 0 $ 333,691,000
A320 and A321          
Property, Plant and Equipment [Line Items]          
Number of aircraft to be sold | aircraft 23 23      
Number of aircraft sold | aircraft 2        
Fixed asset impairment charges | $     $ 282,500,000    
v3.25.0.1
Summary of Significant Accounting Policies - Measurement of Asset Impairments (Details)
 1 Months Ended 12 Months Ended
Jan. 31, 2023
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
aircraft
Property, Plant and Equipment [Line Items]        
Asset impairment-related charges   $ 0 $ 0 $ 333,691,000
Agreement to sell aircraft, expected period 2 years      
Aircraft | Airbus A319        
Property, Plant and Equipment [Line Items]        
Number of aircraft, accelerated retirement | aircraft       29
Aircraft | Impairment due to Planned Acceleration of Plane Retirement | Airbus A319        
Property, Plant and Equipment [Line Items]        
Asset impairment-related charges       $ 333,700,000
v3.25.0.1
Summary of Significant Accounting Policies - Passenger Revenues (Details) - USD ($)
$ in Thousands
 8 Months Ended
Apr. 30, 2024
Dec. 31, 2024
Dec. 31, 2023
Accounting Policies [Abstract]      
Air traffic liability   $ 436,813 $ 383,751
Credit shell term of expiration 90 days 12 months  
v3.25.0.1
Summary of Significant Accounting Policies - Loyalty Program (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
USD ($)
arrangement
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Accounting Policies [Abstract]      
Frequent flyer program, number of types of revenue arrangements | arrangement 2    
Unrecognized revenue from future FREE SPIRIT award redemptions and the sale of mileage credits $ 101,500 $ 104,600  
Consideration received from credit card loyalty programs 85,812 93,147 $ 80,970
Portion of proceeds recognized immediately as marketing component $ 51,220 $ 48,071 $ 40,987
v3.25.0.1
Summary of Significant Accounting Policies - Airframe and Engine Maintenance (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Property, Plant and Equipment [Line Items]      
Deferred costs for heavy maintenance $ 86,400 $ 202,900 $ 149,300
Deferred heavy maintenance, gross 577,300 529,800  
Accumulated heavy maintenance amortization 1,027,872 1,169,021  
Airframe and Engine Maintenance Costs [Abstract]      
Total maintenance, materials and repairs 217,738 223,339 187,820
Utilization-based maintenance expense      
Airframe and Engine Maintenance Costs [Abstract]      
Total maintenance, materials and repairs 103,232 117,458 97,930
Non-utilization-based maintenance expense      
Airframe and Engine Maintenance Costs [Abstract]      
Total maintenance, materials and repairs 114,506 105,881 89,890
Heavy maintenance and major overhaul      
Property, Plant and Equipment [Line Items]      
Amortization of heavy maintenance 113,522 79,768 $ 96,707
Heavy Maintenance      
Property, Plant and Equipment [Line Items]      
Accumulated heavy maintenance amortization $ 273,800 $ 216,200  
v3.25.0.1
Summary of Significant Accounting Policies - Advertising (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Accounting Policies [Abstract]      
Marketing and advertising expenses $ 26.8 $ 9.0 $ 9.2
v3.25.0.1
Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($)
$ in Thousands
Dec. 31, 2024
Dec. 31, 2023
Accounting Policies [Abstract]    
Valuation allowance $ 226,389 $ 17,654
v3.25.0.1
Summary of Significant Accounting Policies - Pratt & Whitney AOG Credits (Details) - PW1100 GTF Engine
$ in Millions
 12 Months Ended
Dec. 31, 2024
USD ($)
Concentration Risk [Line Items]  
Credits related to the aircraft on ground $ 150.6
Credits as a reduction cost 122.2
Credit, expense offset 28.4
Depreciation expense $ 11.4
v3.25.0.1
Summary of Significant Accounting Policies - Concentrations of Risk (Details) - employeeGroup
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Total operating expenses | Aircraft fuel expenditure concentration risk | Fuel Costs      
Concentration Risk [Line Items]      
Concentration of risk 25.00% 31.00% 34.00%
Number of employees, total | Unionized employees concentration risk      
Concentration Risk [Line Items]      
Concentration of risk 84.00%    
Union-represented employee groups 6    
v3.25.0.1
Chapter 11 Proceedings - Voluntary Filing under Chapter 11 Narrative (Details)
Dec. 31, 2024
Nov. 18, 2024
8.00% senior secured notes | 8.00% senior secured notes due in 2025    
Reorganization, Chapter 11 [Line Items]    
Stated interest rate percentage 8.00% 8.00%
v3.25.0.1
Chapter 11 Proceedings - Restructuring Support Agreement Narrative (Details) - USD ($)
$ in Millions
Nov. 18, 2024
Mar. 03, 2025
Dec. 31, 2024
May 12, 2020
Private Placement        
Reorganization, Chapter 11 [Line Items]        
Consideration to be received on sale of shares $ 350.0      
Convertible notes        
Reorganization, Chapter 11 [Line Items]        
Debtor reorganization items, debt equitization $ 385.0      
8.00% senior secured notes | 8.00% senior secured notes due in 2025        
Reorganization, Chapter 11 [Line Items]        
Stated interest rate percentage 8.00%   8.00%  
Debtor reorganization items, debt equitization $ 410.0      
Debtor reorganization items, equity issuance, pro rata share of debtholders 76.00%      
DIP Facility | 8.00% senior secured notes due in 2025 | Revolving credit facility        
Reorganization, Chapter 11 [Line Items]        
Debtor-in-possession financing, amount arranged $ 300.0      
4.75% convertible notes due 2025 | Convertible notes        
Reorganization, Chapter 11 [Line Items]        
Stated interest rate percentage     4.75% 4.75%
Debtor reorganization items, equity issuance, pro rata share of debtholders 24.00%      
Exit Secured Notes | 8.00% senior secured notes due in 2025 | Forecast        
Reorganization, Chapter 11 [Line Items]        
Debtor reorganization items, debt instrument, face amount   $ 840.0    
Stated interest rate percentage, cash   8.00%    
Stated interest rate percentage, paid-in-kind   4.00%    
Exit Secured Notes | 8.00% senior secured notes due in 2025 | Forecast | Senior Secured Noteholders        
Reorganization, Chapter 11 [Line Items]        
Debtor reorganization items, debt instrument, face amount   $ 700.0    
Exit Secured Notes | 8.00% senior secured notes due in 2025 | Forecast | Convertible Noteholders        
Reorganization, Chapter 11 [Line Items]        
Debtor reorganization items, debt instrument, face amount   $ 140.0    
Exit Secured Notes | 8.00% senior secured notes due in 2025 | Forecast | Maximum        
Reorganization, Chapter 11 [Line Items]        
Stated interest rate percentage   12.00%    
Exit Secured Notes | 8.00% senior secured notes due in 2025 | Forecast | Minimum        
Reorganization, Chapter 11 [Line Items]        
Stated interest rate percentage   11.00%    
v3.25.0.1
Chapter 11 Proceedings - Backstop Commitment Agreement Narrative (Details) - Private Placement - USD ($)
$ in Thousands
Nov. 25, 2024
Nov. 18, 2024
Reorganization, Chapter 11 [Line Items]    
Consideration to be received on sale of shares   $ 350,000
Sale of stock, backstopped equity commitment, percent of plan equity value   70.00%
Sale of stock, backstopped equity commitment, solicitation one   $ 175,000
Sale of stock, backstopped equity commitment, solicitation two   175,000
Sale of stock, backstopped equity commitment, backstop premium as percentage of shares issued 10.00%  
Sale of stock, backstopped equity commitment, backstop termination cash payment $ 35,000  
Senior Secured Noteholders    
Reorganization, Chapter 11 [Line Items]    
Sale of stock, backstopped equity commitment, solicitation one   137,810
Sale of stock, backstopped equity commitment, solicitation two   137,810
Sale of stock, backstopped equity commitment, claims executed percent threshold 90.00%  
Sale of stock backstopped equity commitment, claims executed percent threshold, increase in subscription rights $ 248,060  
Sale of stock, backstopped equity commitment, claims executed percent threshold, decrease in direct allocation $ 27,560  
Convertible Noteholders    
Reorganization, Chapter 11 [Line Items]    
Sale of stock, backstopped equity commitment, solicitation one   37,190
Sale of stock, backstopped equity commitment, solicitation two   $ 37,190
Sale of stock, backstopped equity commitment, claims executed percent threshold 90.00%  
Sale of stock backstopped equity commitment, claims executed percent threshold, increase in subscription rights $ 66,940  
Sale of stock, backstopped equity commitment, claims executed percent threshold, decrease in direct allocation $ 7,440  
v3.25.0.1
Chapter 11 Proceedings - Debtor-in-Possession Financing Narrative (Details) - Revolving credit facility - DIP Facility - 8.00% senior secured notes due in 2025
$ in Millions
Nov. 18, 2024
USD ($)
wk
Reorganization, Chapter 11 [Line Items]  
Debtor-in-possession financing, amount arranged | $ $ 300.0
Debtor reorganization items, debt covenant, budget compliance, number of weeks | wk 13
Secured Overnight Financing Rate (SOFR)  
Reorganization, Chapter 11 [Line Items]  
Basis spread on variable rate 7.00%
Base Rate  
Reorganization, Chapter 11 [Line Items]  
Basis spread on variable rate 6.00%
v3.25.0.1
Chapter 11 Proceedings - Equity Rights Offering Narrative (Details) - Private Placement
$ / shares in Units, $ in Millions
Dec. 30, 2024
USD ($)
$ / shares
Reorganization, Chapter 11 [Line Items]  
Consideration received on sale of shares $ 350.0
Sale of stock price per share (in usd per share) | $ / shares $ 14.00
Backstop fee $ 35.0
v3.25.0.1
Chapter 11 Proceedings - Exit Revolving Credit Facility (Details) - Revolving credit facility - Subsequent Event
Jan. 14, 2025
USD ($)
Line of Credit | Secured Overnight Financing Rate (SOFR)  
Reorganization, Chapter 11 [Line Items]  
Basis spread on variable rate 3.25%
Line of Credit | Base Rate  
Reorganization, Chapter 11 [Line Items]  
Basis spread on variable rate 2.25%
Exit Revolving Credit Facility | Line of Credit  
Reorganization, Chapter 11 [Line Items]  
Debt face amount $ 300,000,000
Uncommitted incremental revolving credit facility 25,000,000
Exit Revolving Credit Facility | Letter of Credit  
Reorganization, Chapter 11 [Line Items]  
Debt face amount $ 275,000,000
v3.25.0.1
Chapter 11 Proceedings - Schedule of Liabilities Subject to Compromise (Details) - USD ($)
$ in Thousands
Dec. 31, 2024
Nov. 18, 2024
Dec. 31, 2023
Apr. 30, 2021
Reorganization, Chapter 11 [Line Items]        
Liabilities subject to compromise $ 1,635,104   $ 0  
8.00% senior secured notes | 8.00% senior secured notes due in 2025        
Reorganization, Chapter 11 [Line Items]        
Stated interest rate percentage 8.00% 8.00%    
Liabilities subject to compromise $ 1,110,000      
Convertible Notes Due in 2025 | Convertible notes        
Reorganization, Chapter 11 [Line Items]        
Liabilities subject to compromise $ 25,100      
1.00% convertible notes due 2026 | Convertible notes        
Reorganization, Chapter 11 [Line Items]        
Stated interest rate percentage 1.00%     1.00%
Liabilities subject to compromise $ 500,000      
v3.25.0.1
Chapter 11 Proceedings - Prepetition Charges Narrative (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Reorganizations [Abstract]      
Professional and other fees $ 15,493,000 $ 0 $ 0
v3.25.0.1
Chapter 11 Proceedings - Schedule of Reorganization Expense (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Nov. 18, 2024
Reorganization, Chapter 11 [Line Items]        
Reorganization expense $ 96,780 $ 0 $ 0  
Backstop premium 35,000      
Unamortized debt discounts 20,700      
Unamortized debt issuance costs 9,000      
DIP term loan financing fees 12,600      
Legal, consulting and other fees 19,500      
Total reorganization expense $ 96,780 $ 0 $ 0  
8.00% senior secured notes | Secured Debt        
Reorganization, Chapter 11 [Line Items]        
Stated interest rate percentage 8.00%     8.00%
8.00% senior secured notes | Secured Debt        
Reorganization, Chapter 11 [Line Items]        
Stated interest rate percentage 8.00%      
v3.25.0.1
Special Charges and Credits (Details)
 12 Months Ended
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
aircraft
Jul. 27, 2022
Property, Plant and Equipment [Line Items]        
Special charges (credits) $ 36,029,000 $ 69,537,000 $ 420,172,000  
Special charges, non-operating 15,493,000 0 0  
Airbus A319 | Aircraft        
Property, Plant and Equipment [Line Items]        
Special charges (credits)     $ 333,700,000  
Number of aircraft, accelerated retirement | aircraft     29  
JetBlue Merger Agreement        
Property, Plant and Equipment [Line Items]        
Legal, advisory and other fees 28,100,000 50,000,000.0    
Retention award recorded $ 8,000,000.0 $ 19,500,000    
Frontier Merger Agreement And Merger Agreement With Jet Blue        
Property, Plant and Equipment [Line Items]        
Special charges (credits)     $ 47,200,000  
Frontier Merger Agreement        
Property, Plant and Equipment [Line Items]        
Retention award recorded     $ 39,300,000  
Percentage of target retention bonus to be paid upon merger failure or abandonment       50.00%
v3.25.0.1
Loss (Gain) on Disposal of Assets (Details)
 1 Months Ended 3 Months Ended 12 Months Ended
Oct. 29, 2024
aircraft
Dec. 31, 2023
USD ($)
aircraftLeasebackTransaction
Dec. 31, 2024
aircraftLeasebackTransaction
aircraft
Mar. 31, 2024
aircraftLeasebackTransaction
Mar. 31, 2022
USD ($)
aircraft_engine
Dec. 31, 2024
USD ($)
aircraft
aircraft_engine
aircraftLeasebackTransaction
Dec. 31, 2023
USD ($)
aircraft
aircraftLeasebackTransaction
aircraftEngine
Dec. 31, 2022
USD ($)
aircraftLeasebackTransaction
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                
(Loss) gain on disposal of assets           $ (273,871,000) $ (33,966,000) $ (46,624,000)
Fixed asset impairment charges           $ 0 0 333,691,000
Gain (loss) on sale-leaseback transaction   $ (32,100,000)         (34,000,000.0) $ (38,500,000)
Number of engines sold | aircraft_engine           38    
Number of aircraft related to loss | aircraftLeasebackTransaction               16
Impairment of long-lived assets to be disposed of         $ 6,600,000      
Number of impaired spare engine related to loss on disposal | aircraft_engine         1      
Obsolete Assets                
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                
(Loss) gain on disposal of assets           $ (2,500,000) (3,300,000)  
GAT                
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                
(Loss) gain on disposal of assets           $ (400,000)    
Number of aircraft sold | aircraft           2    
A320 and A321                
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                
Fixed asset impairment charges           $ 282,500,000    
Number of aircraft to be sold | aircraft 23   23          
Number of aircraft sold | aircraft 2              
Airbus A319                
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                
(Loss) gain on disposal of assets           $ (11,900,000) $ (1,600,000)  
Number of aircraft sold | aircraft           17 12  
Number of engines sold | aircraftEngine             20  
Aircraft Leaseback Transaction, New Aircraft Deliveries                
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                
Gain (loss) on sale-leaseback transaction           $ 25,100,000 $ 3,000,000  
Number of aircraft sold | aircraft           8    
Number of aircraft related to loss | aircraftLeasebackTransaction             10  
Aircraft Leaseback Transaction                
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                
(Loss) gain on disposal of assets           $ (1,700,000)    
Additional sale-leaseback transaction | aircraftLeasebackTransaction   20   5        
Number of aircraft on leases | aircraftLeasebackTransaction   6   2        
Failed aircraft sale leaseback | aircraftLeasebackTransaction   14 3 3   3 14  
v3.25.0.1
Letters of Credit (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Jul. 02, 2024
Dec. 31, 2023
Line of Credit Facility [Line Items]      
Restricted cash   $ 200.0  
Standby letter of credit facility | 8.00% senior secured notes due in 2025      
Line of Credit Facility [Line Items]      
Maximum borrowing capacity $ 68.0   $ 85.0
Restricted cash 68.0   75.0
Letter of credit facility, amount outstanding $ 58.8   $ 55.9
v3.25.0.1
Credit Card Processing Arrangements (Details)
$ in Thousands
Jul. 02, 2024
USD ($)
extension
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Restricted Cash and Cash Equivalents Items [Line Items]      
Maximum potential exposure to cash holdbacks by the credit card processors   $ 469,200 $ 408,300
Number of extensions, credit card processing agreement | extension 2    
Extension period, credit card processing agreement 1 year    
Restricted cash $ 200,000    
Cash and cash equivalents   902,057 $ 865,211
Collateral Pledged      
Restricted Cash and Cash Equivalents Items [Line Items]      
Restricted cash $ 50,000    
Cash and cash equivalents   $ 20,700  
v3.25.0.1
Short-term Investment Securities (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]      
Short-term investment securities $ 118,334,000 $ 112,501,000  
Accumulated other comprehensive income (loss) 188,000 (67,000)  
Debt Securities, Available For Sale      
Debt Securities, Available-for-sale [Line Items]      
Short-term investment securities $ 118,300,000 $ 112,500,000  
Weighted-average fixed rate 4.90% 4.50% 1.00%
Unrealized gain on investment securities, net of deferred taxes $ 169,000 $ 298,000  
Realized gain (loss) 0 0  
Accumulated other comprehensive income (loss) $ 201,000 $ (32,000)  
v3.25.0.1
Other Current Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2024
Dec. 31, 2023
Payables and Accruals [Abstract]    
Salaries, wages and benefits $ 187,626 $ 187,723
Federal excise and other passenger taxes and fees payable 110,141 104,447
Aircraft maintenance 103,133 58,800
Airport obligations 66,518 125,278
Backstop premium obligation 35,000 0
Interest payable 26,780 24,732
Aircraft and facility lease obligations 23,926 36,115
Fuel 5,202 64,149
Other 47,513 104,054
Other current liabilities $ 605,839 $ 705,298
v3.25.0.1
Equity - Narrative (Details) - $ / shares
Dec. 31, 2024
Dec. 31, 2023
Class of Stock [Line Items]    
Common stock, shares authorized (in shares) 240,000,000 240,000,000
Common stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Preferred stock, shares authorized (in shares) 10,000,000  
Preferred stock, par value (in dollars per share) $ 0.0001  
Common stock, shares outstanding (in shares) 109,525,063 109,263,005
Preferred stock, shares outstanding (in shares) 0 0
Common Stock, $0.0001 par value    
Class of Stock [Line Items]    
Common stock, shares authorized (in shares) 240,000,000  
Common stock, par value (in dollars per share) $ 0.0001  
Nonvoting common stock    
Class of Stock [Line Items]    
Common stock, shares authorized (in shares) 50,000,000  
Common stock, par value (in dollars per share) $ 0.0001  
Common stock, shares outstanding (in shares) 0 0
v3.25.0.1
Equity - Treasury Stock (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Equity [Abstract]      
Shares repurchased (in shares) 96,000 142,000 107,000
Repurchase of common stock $ 650 $ 2,637 $ 2,359
Number of treasury shares retired (in shares) 0 0 0
v3.25.0.1
Equity - Warrants (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2021
Mar. 10, 2021
Dec. 31, 2020
Dec. 24, 2020
Apr. 09, 2020
Payroll Support Program, CARES Act            
Class of Stock [Line Items]            
Warrants outstanding (in shares)       520,797    
Strike price (in dollars per share)           $ 14.08
Shares of common stock subject to warrants issued to the united states treasury (in shares) 739,089          
Warrants term 5 years          
Number of warrants issued as a percent of outstanding stock 100.00%          
Adjustments to additional paid in capital, warrant issued $ 4.3          
Payroll Support Program 2, CARES Act            
Class of Stock [Line Items]            
Strike price (in dollars per share) $ 19.761       $ 24.42  
Shares of common stock subject to warrants issued to the united states treasury (in shares)   137,753        
Number of securities called by warrants (in shares) 170,230.67          
Payroll Support Program 3, CARES Act            
Class of Stock [Line Items]            
Strike price (in dollars per share) $ 29.496   $ 36.45      
Shares of common stock subject to warrants issued to the united states treasury (in shares)   80,539        
Number of securities called by warrants (in shares) 99,526.95          
Payroll Support Program 1, CARES Act            
Class of Stock [Line Items]            
Strike price (in dollars per share) $ 11.393          
Number of securities called by warrants (in shares) 643,625.2          
v3.25.0.1
Equity- Equity Rights Offering (Details)
$ in Millions
Dec. 30, 2024
USD ($)
Private Placement  
Class of Stock [Line Items]  
Consideration received on sale of shares $ 350.0
v3.25.0.1
Stock-Based Compensation - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Mar. 10, 2021
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated share-based compensation expense   $ 7.2 $ 12.0 $ 11.5
Share-based payment arrangement, expense, tax benefit   $ 0.3 $ 2.4 $ 2.4
Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Period for share issuance after vesting   30 days    
Granted (in shares)   1,140,060 500,648  
Total compensation cost not yet recognized   $ 5.8 $ 8.4  
Total compensation cost not yet recognized, period for recognition   1 year 7 months 6 days 1 year 9 months 18 days  
Granted (in dollars per share)   $ 5.81 $ 19.58 $ 23.48
Total fair value of shares vested   $ 2.2 $ 7.2 $ 7.5
Performance and Market Share Award        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated share-based compensation expense   0.5 3.0 $ 1.5
Total compensation cost not yet recognized   $ 3.5 $ 3.9  
Total compensation cost not yet recognized, period for recognition   1 year 8 months 12 days 1 year 9 months 18 days  
Minimum | Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period   2 years    
Maximum | Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period   3 years    
Equity Incentive Award Plan 2015        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of additional shares authorized (in shares) 3,200,000      
Shares available for future issuance (in shares)   3,691,473 3,123,563  
v3.25.0.1
Stock-Based Compensation - Restricted Stock Activity (Details) - Restricted Stock - $ / shares
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Number of Shares      
Outstanding, beginning balance (in shares) 705,888    
Granted (in shares) 1,140,060 500,648  
Vested (in shares) (336,867)    
Forfeited (in shares) (193,185)    
Outstanding, ending balance (in shares) 1,315,896 705,888  
Weighted-Average Grant Date Fair Value ($)      
Outstanding beginning balance (in dollars per share) $ 20.93    
Granted (in dollars per share) 5.81 $ 19.58 $ 23.48
Vested (in dollars per share) 20.61    
Forfeited (in dollars per share) 12.86    
Outstanding, ending balance (in dollars per share) $ 9.10 $ 20.93  
v3.25.0.1
Earnings (Loss) per Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Numerator:      
Net income (loss) $ (1,229,495) $ (447,464) $ (554,150)
Denominator:      
Weighted-average shares outstanding, basic (in shares) 109,495 109,152 108,751
Effect of dilutive stock awards (in shares) 0 0 0
Adjusted weighted-average shares outstanding, diluted (in shares) 109,495 109,152 108,751
Earnings (loss) per share:      
Basic earnings (loss) per common share (in dollars per share) $ (11.23) $ (4.10) $ (5.10)
Diluted earnings (loss) per common share (in dollars per share) $ (11.23) $ (4.10) $ (5.10)
Anti-dilutive weighted-average shares (in shares) 0 0 0
v3.25.0.1
Debt and Other Obligations - DIP Credit Agreement and Facility (Details) - Revolving credit facility - DIP Credit Agreement and Facility - Line of Credit
Dec. 23, 2024
USD ($)
Debt Instrument, Redemption [Line Items]  
Debt face amount $ 300,000,000
Debt issuance fee $ 9,000,000
Secured Overnight Financing Rate (SOFR)  
Debt Instrument, Redemption [Line Items]  
Basis spread on variable rate 7.00%
Base Rate  
Debt Instrument, Redemption [Line Items]  
Basis spread on variable rate 6.00%
v3.25.0.1
Debt and Other Obligations - Exit Revolving Credit Facility (Details) - Revolving credit facility - Exit Revolving Credit Facility - Subsequent Event
Jan. 14, 2025
USD ($)
Line of Credit  
Debt Instrument [Line Items]  
Debt face amount $ 300,000,000
Uncommitted incremental revolving credit facility 25,000,000
Letter of Credit  
Debt Instrument [Line Items]  
Debt face amount $ 275,000,000
v3.25.0.1
Debt and Other Obligations - Revolving Credit Facility Due In 2026 (Details) - Revolving credit facility - Revolving credit facility due in 2025 - Line of Credit
Mar. 30, 2020
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Debt Instrument [Line Items]      
Line of credit borrowed   $ 300,000,000  
Line of credit facility, remaining borrowing capacity     $ 300,000,000
Debt instrument covenant, unrestricted cash and cash equivalents and unused commitments on all revolving credit facilities $ 450,000,000    
Debt instrument covenant, maximum amount of unused commitments from 2025 credit facility $ 300,000,000    
Debt covenant, collateral coverage ratio 1.0    
Maximum | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate      
Debt Instrument [Line Items]      
Basis spread on variable rate 2.00%    
Maximum | Certain Market Interest Rates      
Debt Instrument [Line Items]      
Basis spread on variable rate 1.00%    
Minimum | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate      
Debt Instrument [Line Items]      
Basis spread on variable rate 0.00%    
Minimum | Certain Market Interest Rates      
Debt Instrument [Line Items]      
Basis spread on variable rate 0.00%    
v3.25.0.1
Debt and Other Obligations - Convertible Senior Notes due 2025 (Details) - 4.75% convertible notes due 2025 - Convertible notes
May 12, 2020
USD ($)
d
aircraft_engine
Dec. 31, 2024
USD ($)
$ / shares
shares
Debt Instrument [Line Items]    
Debt face amount | $ $ 175,000,000  
Stated interest rate percentage 4.75% 4.75%
Conversion price threshold 130.00%  
Number of trading days required for conversion price threshold 20  
Number of consecutive days required for trading days for conversion price threshold 30  
Number of consecutive business days for conversion price threshold 5  
Number of consecutive trading days for conversion price threshold | aircraft_engine 5  
Trading price threshold per principal amount portion 98.00%  
Shares conversion rate per portion of principal amount (in shares) | shares   97.5929
Principal amount portion for trading price threshold | $   $ 1,000
Conversion price (in dollars per share) | $ / shares   $ 10.25
v3.25.0.1
Debt and Other Obligations - Convertible Senior Notes due 2026 (Details)
 12 Months Ended
Apr. 30, 2021
USD ($)
day
$ / shares
shares
Dec. 31, 2024
USD ($)
$ / shares
shares
Debt Instrument [Line Items]    
Derivative liability | $   $ 8,204,000
1.00% convertible notes due 2026 | Convertible notes    
Debt Instrument [Line Items]    
Debt face amount | $ $ 500,000,000.0  
Stated interest rate percentage 1.00% 1.00%
Conversion price threshold 130.00%  
Number of trading days required for conversion price threshold 20  
Number of consecutive days required for trading days for conversion price threshold 30  
Number of consecutive business days for conversion price threshold 5  
Number of consecutive trading days for conversion price threshold 5  
Trading price threshold per principal amount portion 98.00%  
Number of trading days before maturity redemption allowed 40  
Shares conversion rate per portion of principal amount (in shares) | shares 20.3791 25.3578
Principal amount portion for trading price threshold | $ $ 1,000  
Conversion price (in dollars per share) | $ / shares $ 49.07 $ 39.44
v3.25.0.1
Debt and Other Obligations - Schedule of Long-term Debt Instruments (Details)
$ in Millions
Dec. 31, 2024
aircraftLeasebackTransaction
Dec. 31, 2024
Dec. 31, 2024
USD ($)
Dec. 31, 2024
aircraft
Nov. 18, 2024
Dec. 31, 2023
USD ($)
Apr. 30, 2021
May 12, 2020
Debt Instrument [Line Items]                
Long-term debt     $ 2,210.5     $ 3,439.1    
Less current maturities     436.3     315.3    
Less unamortized discount, net     13.2     69.0    
Total     1,761.0     3,054.8    
Aircraft                
Debt Instrument [Line Items]                
Failed aircraft sale leaseback 18     18        
Term Loan | DIP Facility                
Debt Instrument [Line Items]                
Long-term debt     309.0     0.0    
Weighted-average interest rates   11.82%            
8.00% senior secured notes due in 2025 | 8.00% senior secured notes                
Debt Instrument [Line Items]                
Stated interest rate percentage   8.00%     8.00%      
Long-term debt     0.0     $ 1,110.0    
Weighted-average interest rates   8.00%       8.00%    
Fixed-rate term loans due through 2039                
Debt Instrument [Line Items]                
Long-term debt     972.2     $ 1,093.3    
Weighted-average interest rates   6.44%       5.83%    
Unsecured term loans due through 2031 | Payroll Support Program, CARES Act                
Debt Instrument [Line Items]                
Long-term debt     136.3     $ 136.3    
Weighted-average interest rates   1.00%       1.00%    
Fixed-rate class A 2015-1 EETC due through 2028                
Debt Instrument [Line Items]                
Long-term debt     234.6     $ 256.6    
Weighted-average interest rates   4.10%       4.10%    
Fixed-rate class B 2015-1 EETC due through 2024                
Debt Instrument [Line Items]                
Long-term debt     0.0     $ 40.0    
Weighted-average interest rates   4.45%       4.45%    
Fixed-rate class AA 2017-1 EETC due through 2030                
Debt Instrument [Line Items]                
Long-term debt     160.3     $ 172.2    
Weighted-average interest rates   3.38%       3.38%    
Fixed-rate class A 2017-1 EETC due through 2030                
Debt Instrument [Line Items]                
Long-term debt     53.4     $ 57.4    
Weighted-average interest rates   3.65%       3.65%    
Fixed-rate class B 2017-1 EETC due through 2026                
Debt Instrument [Line Items]                
Long-term debt     44.7     $ 48.2    
Weighted-average interest rates   3.80%       3.80%    
Convertible notes | 4.75% convertible notes due 2025                
Debt Instrument [Line Items]                
Stated interest rate percentage   4.75%           4.75%
Long-term debt     0.0     $ 25.1    
Weighted-average interest rates   4.75%       4.75%    
Convertible notes | 1.00% convertible notes due 2026                
Debt Instrument [Line Items]                
Stated interest rate percentage   1.00%         1.00%  
Long-term debt     0.0     $ 500.0    
Weighted-average interest rates   1.00%       1.00%    
Revolving credit facility                
Debt Instrument [Line Items]                
Long-term debt     300.0     $ 0.0    
Revolving credit facility | Revolving credit facility due in 2026                
Debt Instrument [Line Items]                
Long-term debt     $ 300.0     $ 0.0    
Weighted-average interest rates   6.67%            
v3.25.0.1
Debt and Other Obligation - Extinguishment of Debt (Details)
$ in Thousands
 1 Months Ended 3 Months Ended 12 Months Ended
Dec. 31, 2023
aircraftLeasebackTransaction
Dec. 31, 2024
USD ($)
aircraft
aircraftLeasebackTransaction
Mar. 31, 2024
USD ($)
aircraftLeasebackTransaction
aircraft
Dec. 31, 2024
USD ($)
aircraftLeasebackTransaction
Dec. 31, 2023
USD ($)
aircraftLeasebackTransaction
Dec. 31, 2022
USD ($)
Debt Instrument [Line Items]            
Gain (loss) on extinguishment of debt       $ 14,937 $ 15,411 $ 0
Long-term debt   $ 2,210,500   2,210,500    
Fixed Rate Loans            
Debt Instrument [Line Items]            
Extinguishment of debt   $ 17,100 $ 139,600      
Sale leaseback transaction, number of aircraft related to loans | aircraft     5      
Gain (loss) on extinguishment of debt     $ 15,000 $ (100)    
Number of aircraft related to loans extinguished | aircraft   2        
Aircraft Leaseback Transaction            
Debt Instrument [Line Items]            
Additional sale-leaseback transaction | aircraftLeasebackTransaction 20   5      
Number of aircraft on leases | aircraftLeasebackTransaction 6   2      
Failed aircraft sale leaseback | aircraftLeasebackTransaction 14 3 3 3 14  
Long-term debt     $ 123,500      
v3.25.0.1
Debt and Other Obligations - Additional Narrative (Details)
 1 Months Ended 3 Months Ended 12 Months Ended
Dec. 31, 2023
USD ($)
aircraftLeasebackTransaction
Dec. 31, 2024
USD ($)
aircraftLeasebackTransaction
Mar. 31, 2024
USD ($)
aircraftLeasebackTransaction
aircraft
Dec. 31, 2024
USD ($)
aircraftLeasebackTransaction
Dec. 31, 2023
USD ($)
aircraftLeasebackTransaction
Dec. 31, 2022
USD ($)
Debt Instrument [Line Items]            
Repayments of long-term debt       $ 185,400,000 $ 337,500,000  
Gain on extinguishment of debt       14,937,000 15,411,000 $ 0
Current maturities of long-term debt, net, and finance leases $ 315,580,000 $ 436,532,000   436,532,000 $ 315,580,000  
Fixed Rate Loans            
Debt Instrument [Line Items]            
Extinguishment of debt   $ 17,100,000 $ 139,600,000      
Sale leaseback transaction, number of aircraft related to loans | aircraft     5      
Gain on extinguishment of debt     $ 15,000,000 $ (100,000)    
Aircraft Leaseback Transaction            
Debt Instrument [Line Items]            
Additional sale-leaseback transaction | aircraftLeasebackTransaction 20   5      
Number of aircraft on leases | aircraftLeasebackTransaction 6   2      
Failed aircraft sale leaseback | aircraftLeasebackTransaction 14 3 3 3 14  
Corporate credit cards            
Debt Instrument [Line Items]            
Maximum borrowing capacity $ 20,100,000 $ 6,000,000.0   $ 6,000,000.0 $ 20,100,000  
Line of credit, current 1,500,000 900,000   900,000 1,500,000  
Lines of Credit with Counterparties for Jet Fuel and Derivatives            
Debt Instrument [Line Items]            
Maximum borrowing capacity 25,000,000.0 3,500,000   3,500,000 25,000,000.0  
Line of credit, current $ 0 $ 0   $ 0 $ 0  
v3.25.0.1
Debt and Other Obligations - Schedule of Maturities of Long-term Debt (Details)
$ in Millions
Dec. 31, 2024
USD ($)
Debt Disclosure [Abstract]  
2025 $ 415.2
2026 429.1
2027 192.9
2028 257.2
2029 84.8
2030 and beyond 831.3
Long-term debt $ 2,210.5
v3.25.0.1
Debt and Other Obligations - Schedule of Interest Expense on Long-term Debt and Capital Leases (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Nov. 18, 2024
Debt Instrument [Line Items]        
Finance leases $ 33 $ 30 $ 57  
Commitment and other fees 1,340 1,655 2,162  
Amortization of deferred financing costs 13,100 15,453 14,204  
Total 219,094 169,191 139,905  
Accretion of convertible debt and 8.00% senior secured notes 3,821 4,210 1,421  
8.00% senior secured notes due in 2025        
Debt Instrument [Line Items]        
Accretion of convertible debt and 8.00% senior secured notes 3,800 4,200 1,400  
Interest expense $ 88,800 88,800 46,500  
8.00% senior secured notes due in 2025 | 8.00% senior secured notes        
Debt Instrument [Line Items]        
Stated interest rate percentage 8.00%     8.00%
Interest expense $ 92,621 93,010 47,954  
Fixed-rate term loans        
Debt Instrument [Line Items]        
Interest expense 69,635 37,213 41,446  
Unsecured term loans        
Debt Instrument [Line Items]        
Interest expense 1,365 1,363 1,363  
Class A 2015-1 EETC        
Debt Instrument [Line Items]        
Interest expense 10,078 10,962 11,874  
Class B 2015-1 EETC        
Debt Instrument [Line Items]        
Interest expense 446 1,954 2,312  
Class C 2015-1 EETC        
Debt Instrument [Line Items]        
Interest expense 0 777 3,424  
Class AA 2017-1 EETC        
Debt Instrument [Line Items]        
Interest expense 5,561 5,990 6,464  
Class A 2017-1 EETC        
Debt Instrument [Line Items]        
Interest expense 2,005 2,159 2,330  
Class B 2017-1 EETC        
Debt Instrument [Line Items]        
Interest expense 1,748 1,881 2,016  
Class C 2017-1 EETC        
Debt Instrument [Line Items]        
Interest expense 0 522 4,367  
Convertible notes        
Debt Instrument [Line Items]        
Convertible notes 15,849 (3,778) (68)  
Amortization of debt discount and interest expense 16,400 14,300 20,300  
Convertible notes | Convertible Debt Due in 2026        
Debt Instrument [Line Items]        
Offset of market-to-market adjustment 500 18,100 20,300  
Revolving credit facility        
Debt Instrument [Line Items]        
Interest expense 4,501 0 0  
Term Loan | DIP Facility        
Debt Instrument [Line Items]        
Interest expense $ 812 $ 0 $ 0  
v3.25.0.1
Leases - Narrative (Details)
 12 Months Ended
Dec. 31, 2024
USD ($)
aircraft
aircraft_engine
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2024
aircraftLeasebackTransaction
Dec. 31, 2024
aircraft_engine
Dec. 31, 2024
aircraft
Dec. 31, 2024
a
Dec. 31, 2019
USD ($)
a
residential_building_unit
Lessee, Lease, Description [Line Items]                  
Number of aircraft to be sold, held-for-sale | aircraft 21                
Number of spare engines capitalized | aircraft_engine           32      
Total rental expense | $ $ 855,500,000 $ 673,200,000 $ 537,900,000            
Aircraft rent | $ $ 541,909,000 $ 381,239,000 $ 282,428,000            
Cost, Product and Service [Extensible List] Aircraft rent Aircraft rent Aircraft rent            
Supplemental rent expense | $ $ 36,200,000 $ 14,000,000.0 $ 16,500,000            
Area of land | a               8.5 8.5
Land | $                 $ 41,000,000.0
Operating lease not yet commenced, amount, 2025 | $       $ 2,800,000          
Operating lease not yet commenced, amount, 2026 and beyond | $       $ 0          
Third Party Lessor                  
Lessee, Lease, Description [Line Items]                  
Number of delivered leased aircraft | aircraft 19                
Asset Pledged as Collateral                  
Lessee, Lease, Description [Line Items]                  
Number of spare engines capitalized were pledged as collateral | aircraft_engine           21      
Aircraft                  
Lessee, Lease, Description [Line Items]                  
Failed aircraft sale leaseback         18   18    
A320 Family                  
Lessee, Lease, Description [Line Items]                  
Number of aircraft held | aircraft_engine           192      
A320 Family | Aircraft                  
Lessee, Lease, Description [Line Items]                  
Number of aircraft owned | aircraft             49    
Number of aircraft unencumbered | aircraft             0    
Aircraft                  
Lessee, Lease, Description [Line Items]                  
Number of aircraft under sale-leaseback transactions | aircraft 8                
Aircraft | A320 Family                  
Lessee, Lease, Description [Line Items]                  
Number of aircraft under operating lease | aircraft             146    
Aircraft | Minimum                  
Lessee, Lease, Description [Line Items]                  
Operating lease contract term 4 years                
Aircraft | Maximum                  
Lessee, Lease, Description [Line Items]                  
Operating lease contract term 18 years                
Other                  
Lessee, Lease, Description [Line Items]                  
Area of land | a                 2.6
Number of residential building unit expected to be built | residential_building_unit                 200
Other | Maximum                  
Lessee, Lease, Description [Line Items]                  
Operating lease contract term 99 years               99 years
Spare engines                  
Lessee, Lease, Description [Line Items]                  
Number of aircraft under operating lease | aircraft_engine           5      
Number of engines purchased with cash | aircraft_engine 3                
Number of spare engines purchased off lease | aircraft_engine 1                
Leased Computer And Office Equipment | Minimum                  
Lessee, Lease, Description [Line Items]                  
Finance lease contract term 4 years                
Leased Computer And Office Equipment | Maximum                  
Lessee, Lease, Description [Line Items]                  
Finance lease contract term 5 years                
v3.25.0.1
Leases - Schedule of Future Minimum Lease Payments Under Finance and Operating Leases (Details) - USD ($)
$ in Thousands
Dec. 31, 2024
Dec. 31, 2023
Finance Leases    
2025 $ 219  
2026 141  
2027 93  
2028 67  
2029 6  
2030 and thereafter 0  
Total minimum lease payments 526  
Less amount representing interest 50  
Present value of minimum lease payments 476  
Less current portion 195  
Long-term portion 281  
Operating Leases    
Less current portion 257,796 $ 224,865
Long-term portion 4,335,106 $ 3,298,871
Total Operating and Finance Lease Obligations    
2025 569,306  
2026 543,991  
2027 527,184  
2028 505,009  
2029 489,016  
2030 and thereafter 4,984,543  
Total minimum lease payments 7,619,049  
Less amount representing interest 3,025,671  
Present value of minimum lease payments 4,593,378  
Less current portion 257,991  
Long-term portion $ 4,335,387  
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration] Long-Term Debt and Lease Obligation, Including Current Maturities  
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Current maturities of long-term debt, net, and finance leases  
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Long-term debt and finance leases, less current maturities  
Aircraft and Spare Engine Leases    
Operating Leases    
2025 $ 564,040  
2026 538,911  
2027 522,951  
2028 502,185  
2029 486,881  
2030 and thereafter 4,842,905  
Total minimum lease payments 7,457,873  
Less amount representing interest 2,893,031  
Present value of minimum lease payments 4,564,842  
Less current portion 254,521  
Long-term portion 4,310,321  
Property Facility Leases    
Operating Leases    
2025 5,047  
2026 4,939  
2027 4,140  
2028 2,757  
2029 2,129  
2030 and thereafter 141,638  
Total minimum lease payments 160,650  
Less amount representing interest 132,590  
Present value of minimum lease payments 28,060  
Less current portion 3,275  
Long-term portion $ 24,785  
v3.25.0.1
Leases - Schedule of Lease Costs, Lease Terms and Discount Rates (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Finance lease cost      
Amortization of leased assets $ 277 $ 451  
Interest of lease liabilities 33 30 $ 57
Operating lease cost      
Operating lease cost 517,016 377,505  
Short-term lease cost 37,294 39,916  
Variable lease cost 272,087 227,030  
Total lease cost $ 826,707 $ 644,932  
Weighted-average remaining lease term      
Operating leases 15 years 1 month 6 days 14 years 9 months 18 days  
Finance leases 2 years 10 months 24 days 2 years 3 months 18 days  
Weighted-average discount rate      
Operating leases 7.11% 6.84%  
Finance leases 5.91% 4.25%  
v3.25.0.1
Defined Contribution 401(k) Plan (Details)
$ in Millions
 1 Months Ended 12 Months Ended
Jan. 01, 2024
Mar. 01, 2018
Mar. 31, 2022
Dec. 31, 2024
USD ($)
plan
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Defined Contribution Plan Disclosure [Line Items]            
Defined contribution 401(k) plan, number of plans | plan       3    
Defined contribution 401(k) plan, requisite service period       60 days    
Defined contribution 401(k) plan, requisite age       21 years    
Defined contribution 401(k) plan, matching contributions made in period | $       $ 128.5 $ 112.4 $ 88.9
Spirit Airlines, Inc. Pilots’ Retirement Savings Plan            
Defined Contribution Plan Disclosure [Line Items]            
Defined contribution 401(k) plan, employer contribution, percent of employees' gross pay 16.00% 11.00% 15.00%      
Defined contribution 401(k) plan, employer contribution, percent of employees' gross pay, annual percentage increase   1.00%        
v3.25.0.1
Income Taxes - Schedule of Significant Components of the Provision for Income Taxes from Continuing Operations (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Current:      
Federal $ (5,438) $ 5,449 $ 0
State and local (40) 1,309 327
Foreign 3,485 1,350 1,695
Total current expense (benefit) (1,993) 8,108 2,022
Deferred:      
Federal (54,922) (115,905) (141,251)
State and local (3,293) (3,334) (7,360)
Total deferred expense (benefit) (58,215) (119,239) (148,611)
Total income tax expense (benefit) $ (60,208) $ (111,131) $ (146,589)
v3.25.0.1
Income Taxes - Schedule of Reconciliation of Income Tax Expense (Details)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Reconciliation of Income Tax Expense      
Expected provision at federal statutory tax rate 21.00% 21.00% 21.00%
State tax expense, net of federal benefit 1.30% 1.50% 1.60%
Permanent tax differences (1.60%) (1.30%) (0.60%)
Valuation allowance (16.10%) (1.20%) (0.80%)
Other 0.10% (0.10%) (0.30%)
Total income tax expense (benefit) 4.70% 19.90% 20.90%
v3.25.0.1
Income Taxes - Schedule of Deferred Taxes (Details) - USD ($)
$ in Thousands
Dec. 31, 2024
Dec. 31, 2023
Deferred tax assets:    
Income tax credits $ 2,441 $ 4,298
Net operating losses 437,400 328,977
Deferred revenue 22,641 25,924
Nondeductible accruals 29,936 32,899
Deferred manufacturing credits 13,415 14,556
Loan liability 140,313 115,161
Operating lease liability 1,053,684 797,778
Interest expense 70,011 51,305
Other 17,496 38,910
Valuation allowance (226,389) (17,654)
Deferred tax assets 1,560,948 1,392,154
Deferred tax liabilities:    
Property, plant and equipment 513,028 612,571
Accrued aircraft and engine maintenance 54,574 70,997
Right-of-use asset 1,042,099 803,232
Other 3,174 13,115
Deferred tax liabilities 1,612,875 1,499,915
Net deferred tax assets (liabilities) $ (51,927) $ (107,761)
v3.25.0.1
Income Taxes - Narrative (Details) - USD ($)
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Summary Of Income Taxes [Line Items]      
Valuation allowance $ 226,389,000 $ 17,654,000  
Foreign tax credits 900,000    
State net operating losses 1,400,000    
Liability recorded for interest and penalties on unrecognized tax benefits 0 $ 0 $ 0
Domestic Tax Jurisdiction      
Summary Of Income Taxes [Line Items]      
Operating loss carryforwards 1,900,000,000    
State and Local Jurisdiction      
Summary Of Income Taxes [Line Items]      
Operating loss carryforwards $ 862,000,000.0    
v3.25.0.1
Commitments and Contingencies - Aircraft-Related Commitments and Financing Arrangements (Details)
$ in Millions
Jul. 30, 2024
USD ($)
aircraft
Dec. 31, 2024
USD ($)
aircraft
aircraft_engine
Nov. 18, 2024
Committed Expenditures      
Committed expenditures, 2025   $ 2.8  
Aircraft-Related Secured Debt      
Interest Commitments      
Interest commitments, 2025   72.3  
Interest commitments, 2026   77.5  
Interest commitments, 2027   71.4  
Interest commitments, 2028   63.2  
Interest commitments, 2029   56.8  
Interest commitments, 2030 and beyond   $ 102.8  
8.00% senior secured notes due in 2025 | 8.00% senior secured notes      
Interest Commitments      
Stated interest rate percentage   8.00% 8.00%
Non-Aircraft-Related Secured Debt, Unsecured Debt And Convertible Debt      
Interest Commitments      
Interest commitments, 2025   $ 3.8  
Interest commitments, 2026   3.4  
Interest commitments, 2027   3.4  
Interest commitments, 2028   3.4  
Interest commitments, 2029   3.4  
Interest commitments, 2030 and beyond   3.7  
Aircraft and Related Flight Equipment      
Committed Expenditures      
Committed expenditures, 2025   153.3  
Committed expenditures, 2026   12.3  
Committed expenditures, 2027   183.0  
Committed expenditures, 2028   297.8  
Committed expenditures, 2029   1,124.3  
Committed expenditures, 2030 and beyond   1,857.8  
Non-aircraft Related Commitments      
Committed Expenditures      
Committed expenditures, 2025   41.1  
Committed expenditures, 2026   24.0  
Committed expenditures, 2027   18.5  
Committed expenditures, 2028   2.0  
Committed expenditures, 2029   0.1  
Committed expenditures, 2030 and beyond   $ 0.0  
2027 Through 2028 | Leased Aircraft      
Unrecorded Unconditional Purchase Obligation [Line Items]      
Number of aircraft under direct lease transaction | aircraft 36    
2029 Through 2031 | Other Aircraft      
Unrecorded Unconditional Purchase Obligation [Line Items]      
Number of aircraft under direct lease transaction | aircraft 52    
Proceeds received from lease and purchase agreement $ 186.0    
PurePower PW1100G-JM Engine | 2025 Through 2031      
Unrecorded Unconditional Purchase Obligation [Line Items]      
Number of spare aircraft engines ordered | aircraft_engine   16  
A320 and A321      
Aircraft Rent Commitments [Abstract]      
Number of delivered aircraft with secured debt financing commitments | aircraft   67  
Airbus | 2025 Through 2031      
Unrecorded Unconditional Purchase Obligation [Line Items]      
Future aircraft to be received | aircraft   55  
Number of aircraft without secured financing commitments scheduled for delivery | aircraft   52  
Airbus | Through 2025 Deliveries      
Unrecorded Unconditional Purchase Obligation [Line Items]      
Number of aircraft with secured debt financing commitments scheduled for delivery | aircraft   3  
Third Party Lessor | A320 and A321 | 2025 Through 2028      
Unrecorded Unconditional Purchase Obligation [Line Items]      
Future aircraft to be received | aircraft   39  
Third Party Lessor | A320NEO      
Aircraft Rent Commitments [Abstract]      
Aircraft rent commitments, 2024   $ 20.5  
Aircraft rent commitments, 2025   27.1  
Aircraft rent commitments, 2026   88.3  
Aircraft rent commitments, 2027   183.3  
Aircraft rent commitments, 2028   229.4  
Aircraft rent commitments, 2029 and beyond   $ 2,204.1  
v3.25.0.1
Commitments and Contingencies - Litigation and Assessments (Details) - USD ($)
 1 Months Ended 3 Months Ended 12 Months Ended
Jun. 30, 2023
Sep. 30, 2024
Mar. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
Jul. 19, 2022
Mar. 31, 2022
Loss Contingencies [Line Items]              
Loss contingency, estimate of possible loss         $ 6,000,000    
Loss contingency accrual, period decrease excluding payments   $ 300,000 $ 1,400,000        
Loss contingency accrual, payments       $ 4,300,000      
Internal revenue service federal excise taxes           $ 27,500,000 $ 34,900,000
Recognized a loss contingency       $ 0      
Maximum              
Loss Contingencies [Line Items]              
Tentative settlement amount $ 8,300,000            
v3.25.0.1
Commitments and Contingencies - Employees (Details)
$ in Millions
 1 Months Ended 3 Months Ended 12 Months Ended
Jan. 31, 2025
pilot
Sep. 01, 2024
pilot
Jan. 31, 2025
employee
Jul. 31, 2024
Dec. 31, 2024
USD ($)
employeeGroup
employee
Sep. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
employeeGroup
employee
Dec. 31, 2023
USD ($)
Concentration Risk [Line Items]                
Number of pilots furloughed | pilot   170            
Severance costs | $         $ 3.5 $ 1.4    
Subsequent Event                
Concentration Risk [Line Items]                
Number of additional pilots furloughed | pilot 300              
Number of positions from various departments | employee     200          
Health Insurance Product Line                
Concentration Risk [Line Items]                
Accrued health care claims | $         $ 11.6   $ 11.6 $ 9.1
Professional Airline Flight Control Association (PAFCA)                
Concentration Risk [Line Items]                
Employee union contract term       2 years        
Aircraft Mechanics Fraternal Association                
Concentration Risk [Line Items]                
Number of employees included n union application (approximately) | employee         640   640  
Number of employees, total | Unionized employees concentration risk                
Concentration Risk [Line Items]                
Union-represented employee groups | employeeGroup         6   6  
Concentration of risk             84.00%  
Number of employees, total | Unionized employees concentration risk | Air Line Pilots Association, International (ALPA)                
Concentration Risk [Line Items]                
Concentration of risk             27.00%  
Number of employees, total | Unionized employees concentration risk | Association of Flight Attendants (AFA-CWA)                
Concentration Risk [Line Items]                
Concentration of risk             44.00%  
Number of employees, total | Unionized employees concentration risk | Professional Airline Flight Control Association (PAFCA)                
Concentration Risk [Line Items]                
Concentration of risk             1.00%  
Number of employees, total | Unionized employees concentration risk | International Association of Machinists and Aerospace Workers (IAMAW)                
Concentration Risk [Line Items]                
Concentration of risk             3.00%  
Number of employees, total | Unionized employees concentration risk | Transport Workers Union of America (TWU)                
Concentration Risk [Line Items]                
Concentration of risk             3.00%  
Number of employees, total | Unionized employees concentration risk | Aircraft Mechanics Fraternal Association (AMFA)                
Concentration Risk [Line Items]                
Concentration of risk             6.00%  
v3.25.0.1
Fair Value Measurements - Long-term Debt (Details) - USD ($)
$ in Thousands
Dec. 31, 2024
Nov. 18, 2024
Dec. 31, 2023
Apr. 30, 2021
May 12, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value $ 2,210,500   $ 3,439,100    
Carrying Value 1,635,104   0    
Estimated Fair Value 1,293,100        
Debt Classified as Liabilities Subject to Compromise in Current Year          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value     1,635,100    
Estimated Fair Value     1,514,100    
Term Loan | DIP Facility          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 309,000   0    
Term Loan | Estimated Fair Value | Level 3 | DIP Facility          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 309,000   0    
Fixed-rate term loans          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 972,200   1,093,300    
Fixed-rate term loans | Estimated Fair Value | Level 3          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 970,700   1,099,900    
Unsecured term loans | Unsecured term loans          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 136,300   136,300    
Unsecured term loans | Estimated Fair Value | Level 3 | Unsecured term loans          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 130,400   128,300    
2015-1 EETC Class A          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 234,600   256,600    
2015-1 EETC Class A | Estimated Fair Value | Level 2          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 215,800   230,800    
2015-1 EETC Class B          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 0   40,000    
2015-1 EETC Class B | Estimated Fair Value | Level 2          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 0   39,400    
2017-1 EETC Class AA          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 160,300   172,200    
2017-1 EETC Class AA | Estimated Fair Value | Level 2          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 140,400   149,600    
2017-1 EETC Class A          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 53,400   57,400    
2017-1 EETC Class A | Estimated Fair Value | Level 2          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 45,800   48,500    
2017-1 EETC Class B          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 44,700   48,200    
2017-1 EETC Class B | Estimated Fair Value | Level 2          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 40,500   42,900    
Revolving credit facility          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 300,000   0    
Revolving credit facility | Estimated Fair Value | Level 3          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 300,000   0    
8.00% senior secured notes due in 2025 | 8.00% senior secured notes          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value $ 0   1,110,000    
Stated interest rate percentage 8.00% 8.00%      
Carrying Value $ 1,110,000        
8.00% senior secured notes due in 2025 | 8.00% senior secured notes | Debt Classified as Liabilities Subject to Compromise in Current Year          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value     1,110,000    
8.00% senior secured notes due in 2025 | Estimated Fair Value | Level 3 | 8.00% senior secured notes          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 1,117,900        
8.00% senior secured notes due in 2025 | Estimated Fair Value | Level 3 | 8.00% senior secured notes | Debt Classified as Liabilities Subject to Compromise in Current Year          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value     1,121,900    
Convertible notes | 4.75% convertible notes due 2025          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value $ 0   25,100    
Stated interest rate percentage 4.75%       4.75%
Carrying Value $ 25,100        
Convertible notes | 4.75% convertible notes due 2025 | Debt Classified as Liabilities Subject to Compromise in Current Year          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value     25,100    
Convertible notes | 1.00% convertible notes due 2026          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value $ 0   500,000    
Stated interest rate percentage 1.00%     1.00%  
Carrying Value $ 500,000        
Convertible notes | 1.00% convertible notes due 2026 | Debt Classified as Liabilities Subject to Compromise in Current Year          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value     500,000    
Convertible notes | Estimated Fair Value | Level 2 | 4.75% convertible notes due 2025          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 8,800        
Convertible notes | Estimated Fair Value | Level 2 | 4.75% convertible notes due 2025 | Debt Classified as Liabilities Subject to Compromise in Current Year          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value     42,300    
Convertible notes | Estimated Fair Value | Level 2 | 1.00% convertible notes due 2026          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value 166,400        
Convertible notes | Estimated Fair Value | Level 2 | 1.00% convertible notes due 2026 | Debt Classified as Liabilities Subject to Compromise in Current Year          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value     349,900    
Long Term Debt Excluding Liabilities Subject To Compromise          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Carrying Value 2,210,500   1,804,000    
Long Term Debt Excluding Liabilities Subject To Compromise | Estimated Fair Value          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Estimated Fair Value $ 2,152,600   $ 1,739,400    
v3.25.0.1
Fair Value Measurements - Narrative (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
Nov. 18, 2024
Jul. 02, 2024
Apr. 30, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Restricted cash         $ 200,000  
Derivative liability   $ 8,204        
Collateral Pledged            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Restricted cash         $ 50,000  
Control Agreements For Interest And Fee Payments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Restricted cash   44,400        
Corporate credit cards | Collateral Pledged            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Restricted cash   6,000        
Credit Card Processing Agreement | Collateral Pledged            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Restricted cash   $ 50,000        
8.00% senior secured notes due in 2025 | 8.00% senior secured notes            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Stated interest rate percentage   8.00%   8.00%    
Convertible notes | 1.00% convertible notes due 2026            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Stated interest rate percentage   1.00%       1.00%
Convertible notes | 1.00% convertible notes due 2026 | Level 2            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Favorable mark to market adjustments, derivative liability $ 500   $ 18,100      
Standby letter of credit facility | 8.00% senior secured notes due in 2025            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Maximum borrowing capacity   $ 68,000 85,000      
Restricted cash   68,000 75,000      
Letter of credit facility, amount outstanding   $ 58,800 $ 55,900      
v3.25.0.1
Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Liability Statement Of Financial Position Extensible Enumeration Not Disclosed Flag Derivative liability  
Recurring basis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents $ 865.2 $ 902.1
Restricted cash 119.4 168.4
Short-term investment securities 112.5 118.3
Assets held for sale 1.8 463.0
Total assets 1,098.9 1,651.8
Derivative liability 11.1  
Total liabilities 11.1 0.0
Recurring basis | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents 865.2 902.1
Restricted cash 119.4 168.4
Short-term investment securities 112.5 118.3
Assets held for sale 0.0 0.0
Total assets 1,097.1 1,188.8
Derivative liability 0.0  
Total liabilities 0.0 0.0
Recurring basis | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents 0.0 0.0
Restricted cash 0.0 0.0
Short-term investment securities 0.0 0.0
Assets held for sale 0.0 0.0
Total assets 0.0 0.0
Derivative liability 11.1  
Total liabilities 11.1 0.0
Recurring basis | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents 0.0 0.0
Restricted cash 0.0 0.0
Short-term investment securities 0.0 0.0
Assets held for sale 1.8 463.0
Total assets 1.8 463.0
Derivative liability 0.0  
Total liabilities $ 0.0 $ 0.0
v3.25.0.1
Operating Segments and Related Disclosures - Schedule of Geographic Revenues (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Revenues from External Customers and Long-Lived Assets [Line Items]      
Total operating revenues $ 4,913,421 $ 5,362,549 $ 5,068,447
DOT—Domestic      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Total operating revenues 4,358,200 4,676,100 4,371,800
DOT—Latin America and Caribbean      
Revenues from External Customers and Long-Lived Assets [Line Items]      
Total operating revenues $ 555,200 $ 686,400 $ 696,600
v3.25.0.1
Operating Segments and Related Disclosures - Foreign Revenues (Details)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Total passenger revenue | Any individual foreign country | One Foreign Country | Maximum      
Concentration Risk [Line Items]      
Concentration of risk (greater than) 4.00% 4.00% 4.00%