v3.25.3
Comprehensive Income - Schedule of Reclassifications (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Line Items]        
Fuel and oil expense $ 1,331 $ 1,417 $ 3,907 $ 4,548
Tax expense 14 22 37 65
Other operating expenses 1,123 1,079 3,346 3,188
Net of tax 54 $ 67 118 $ 204
Amounts reclassified from AOCI        
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Line Items]        
Net of tax 29   88  
Fuel derivatives | Fuel derivatives | Amounts reclassified from AOCI        
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Line Items]        
Fuel and oil expense 36   110  
Tax expense 8   26  
Net of tax 28   84  
Other | Fuel derivatives | Amounts reclassified from AOCI        
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Line Items]        
Tax expense 1   1  
Other operating expenses 2   5  
Net of tax $ 1   $ 4