Operating Leases - Aircraft (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) aircraft engine	Dec. 31, 2023 USD ($) aircraft engine	Dec. 31, 2022 USD ($) engine aircraft
Lessee, Lease, Description [Line Items]
Gains recognized on sale-leaseback transactions | $	$ 294	$ 147	$ 87
A320neo
Lessee, Lease, Description [Line Items]
Number of leases in period | aircraft	0	10	0
Aircraft and spare engines
Lessee, Lease, Description [Line Items]
Number of leases | aircraft	159
Aircraft and spare engines | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	2 months
Aircraft and spare engines | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	12 years
Aircraft and spare engines | A-320 | Aircraft Sale Leaseback
Lessee, Lease, Description [Line Items]
Number of sale-leaseback transactions | aircraft	23	11	13
Aircraft Engine
Lessee, Lease, Description [Line Items]
Number of leases | engine	34
Number of engines dependent on usage-based metrics | engine	8
Aircraft Engine | Aircraft Sale Leaseback
Lessee, Lease, Description [Line Items]
Number of sale-leaseback transactions | engine	5	4	4
Aircraft Engine | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	1 month
Aircraft Engine | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	12 years
Aircraft and Aircraft Engines
Lessee, Lease, Description [Line Items]
Gains recognized on sale-leaseback transactions | $	$ 294	$ 147	$ 87