v3.26.3
DEBT - Narrative (Details) - USD ($)
9 Months Ended
Oct. 16, 2026
Jun. 23, 2026
Feb. 06, 2026
Feb. 03, 2026
Feb. 02, 2026
Sep. 30, 2026
Feb. 24, 2026
Debt Instrument [Line Items]              
Unamortized debt discount, premiums and debt issuance costs           $ 152,000,000  
Secured Debt | Term Loan Credit and guaranty Agreement | Secured Overnight Financing Rate (SOFR)              
Debt Instrument [Line Items]              
Basis spread on variable rate       1.75% 2.00%    
Secured Debt | Term Loan Credit and guaranty Agreement | Other Market Rates              
Debt Instrument [Line Items]              
Basis spread on variable rate       0.75% 1.00%    
Secured Debt | Aircraft Purchase Financing              
Debt Instrument [Line Items]              
Proceeds from issuance of debt           $ 4,600,000,000  
Secured Debt | Aircraft Purchase Financing | Weighted Average              
Debt Instrument [Line Items]              
Basis spread on variable rate           1.40%  
Senior Notes              
Debt Instrument [Line Items]              
Repayments of debt           $ 4,900,000,000  
Senior Notes | 4.625% Senior Secured Notes due 2029              
Debt Instrument [Line Items]              
Stated interest rate (in percent)           4.625%  
Senior Notes | 2031 Notes              
Debt Instrument [Line Items]              
Stated interest rate (in percent)         5.375%    
Face amount         $ 1,000,000,000    
Percentage of principal amount bearing fixed interest rate         100.00%    
Senior Notes | 2031 Notes | Debt Instrument, Redemption, Period One              
Debt Instrument [Line Items]              
Redemption price percentage of principal amount         100.00%    
Senior Notes | 2031 Notes | Debt Instrument, Redemption, Period Two              
Debt Instrument [Line Items]              
Redemption price percentage of principal amount         100.00%    
Senior Notes | 2029 Notes              
Debt Instrument [Line Items]              
Stated interest rate (in percent)     4.875%        
Face amount     $ 1,000,000,000        
Percentage of principal amount bearing fixed interest rate     100.00%        
Senior Notes | 2029 Notes | Debt Instrument, Redemption, Period One              
Debt Instrument [Line Items]              
Redemption price percentage of principal amount     100.00%        
Senior Notes | 2029 Notes | Debt Instrument, Redemption, Period Two              
Debt Instrument [Line Items]              
Redemption price percentage of principal amount     100.00%        
Senior Notes | Aircraft Purchase Financing              
Debt Instrument [Line Items]              
Repayments of debt           $ 500,000,000  
Senior Notes | 2026 Notes              
Debt Instrument [Line Items]              
Stated interest rate (in percent)             4.375%
Redemption of aggregate principal amount of outstanding debt             $ 2,000,000,000.0
Senior Notes | 2029 Notes              
Debt Instrument [Line Items]              
Stated interest rate (in percent)             4.625%
Senior Notes | Payroll Support Program Notes, Due 2030              
Debt Instrument [Line Items]              
Face amount   $ 1,500,000,000          
Repayments of debt   600,000,000          
Unsecured Debt | Payroll Support Program Note 1, Due 2031              
Debt Instrument [Line Items]              
Face amount   900,000,000          
Unsecured Debt | Payroll Support Program Note 2, Due 2031              
Debt Instrument [Line Items]              
Face amount   $ 800,000,000          
Revolving Credit Facility | Secured Debt              
Debt Instrument [Line Items]              
Undrawn and available amount under revolving credit facility           3,000,000,000.0  
Maximum borrowing capacity           $ 3,000,000,000.0  
Revolving Credit Facility | Secured Debt | Subsequent Event              
Debt Instrument [Line Items]              
Maximum borrowing capacity $ 5,000,000,000.0            
Revolving Credit Facility | Secured Debt | Subsequent Event | Minimum              
Debt Instrument [Line Items]              
Commitment fee percentage 0.08%            
Revolving Credit Facility | Secured Debt | Subsequent Event | Maximum              
Debt Instrument [Line Items]              
Commitment fee percentage 0.275%