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DEBT - Narrative (Details) |  |  |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | ---
Nov. 01, 2024 USD ($) | Jul. 02, 2024 USD ($) | Feb. 22, 2024 USD ($) | Feb. 15, 2024 USD ($) | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Aug. 05, 2024 USD ($) series aircraft | Apr. 16, 2024 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Repayments of long-term debt |  |  |  |  | $ 10,138,000,000 | $ 4,248,000,000 | $ 4,011,000,000 |  |
Unrestricted liquidity required for credit agreement |  |  |  |  | $ 2,000,000,000 |  |  |  |
Minimum ratio of appraised value of collateral for Credit Agreement |  |  |  |  | 1.6 |  |  |  |
Secured Debt | Term Loan Facility |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Repayments of long-term debt |  | $ 1,800,000,000 |  |  |  | $ 1,000,000,000 |  |  |
Proceeds from issuance of debt |  |  | $ 2,500,000,000 |  |  |  |  |  |
Secured Debt | 2021 Term Loans |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Repayments of long-term debt |  |  | $ 1,370,000,000 |  |  |  |  |  |
Percent spread on variable rate |  |  |  |  | 2.00% |  |  |  |
Secured Debt | 2024 Term Loans |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Repayments of long-term debt | $ 400,000,000 |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  | 6.63% |  |  |  |
Secured Debt | Aircraft Purchase Financing |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Aggregate principal amount of debt |  |  |  |  |  |  |  | $ 1,400,000,000 |
Number of aircrafts financed | aircraft |  |  |  |  |  |  |  | 48 |
Number of indenture note series | series |  |  |  |  |  |  |  | 2 |
Secured Debt | Series AA |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  | 5.45% |
Aggregate principal amount of debt |  |  |  |  |  |  |  | $ 969,000,000 |
Secured Debt | Series A |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  | 5.875% |
Aggregate principal amount of debt |  |  |  |  |  |  |  | $ 385,000,000 |
Secured Debt | 2026 Notes |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  | 4.375% |  |  |  |
Secured Debt | 2029 Notes |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  | 4.625% |  |  |  |
Secured Debt | Aircraft Purchase Financing |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Proceeds from issuance of debt |  |  |  |  | $ 1,400,000,000 |  |  |  |
Secured Debt | Minimum | Aircraft Purchase Financing |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Percent spread on variable rate |  |  |  |  | 6.17% |  |  |  |
Secured Debt | Maximum | Aircraft Purchase Financing |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Percent spread on variable rate |  |  |  |  | 6.51% |  |  |  |
Secured Debt | Secured Overnight Financing Rate (SOFR) | 2024 Term Loans |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Percent spread on variable rate | 2.00% |  | 2.75% |  |  |  |  |  |
Debt instrument, interest rate floor |  |  | 0.00% |  |  |  |  |  |
Secured Debt | Other Market Rates | 2024 Term Loans |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Percent spread on variable rate | 1.00% |  | 1.75% |  |  |  |  |  |
Debt instrument, interest rate floor |  |  | 1.00% |  |  |  |  |  |
Secured Debt | Revolving Credit Facility |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Line of credit facility, increase (decrease) in maximum borrowing capacity |  |  |  | $ 1,115,000,000 |  |  |  |  | $ 100,000,000
Maximum borrowing capacity |  |  |  | $ 2,865,000,000 |  |  |  |  | 2,965,000,000
Maximum borrowing capacity of portion involving extension of maturity |  |  |  |  |  |  |  |  | 150,000,000
Undrawn and available amount under revolving credit facility |  |  |  |  | $ 2,965,000,000 |  |  |  |
Secured Debt | Revolving Credit Facility | Extending Lenders |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  |  |  |  |  |  |  | 2,950,000,000
Secured Debt | Revolving Credit Facility | Non-Extending Lenders |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  |  |  |  |  |  |  | $ 15,000,000
Secured Debt | Revolving Credit Facility | Non-Extending Lenders | Secured Overnight Financing Rate (SOFR) | Minimum |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Percent spread on variable rate |  |  |  | 3.00% |  |  |  |  |
Secured Debt | Revolving Credit Facility | Non-Extending Lenders | Secured Overnight Financing Rate (SOFR) | Maximum |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Percent spread on variable rate |  |  |  | 3.50% |  |  |  |  |
Secured Debt | Revolving Credit Facility | Non-Extending Lenders | Other Market Rates | Minimum |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Percent spread on variable rate |  |  |  | 2.00% |  |  |  |  |
Secured Debt | Revolving Credit Facility | Non-Extending Lenders | Other Market Rates | Maximum |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Percent spread on variable rate |  |  |  | 2.50% |  |  |  |  |

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