Operating Leases - Aircraft (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($) aircraft engine lease transaction	Mar. 31, 2023 USD ($) lease transaction aircraft
Lessee, Lease, Description [Line Items]
Gains recognized on sale-leaseback transactions | $	$ 71	$ 40
Aircraft
Lessee, Lease, Description [Line Items]
Number of leases | lease	142
Aircraft | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	11 months
Aircraft | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	12 years
Aircraft Engine
Lessee, Lease, Description [Line Items]
Number of leases | lease	32
Number of engines dependent on usage-based metrics | engine	11
Aircraft Engine | Aircraft Sale Leaseback
Lessee, Lease, Description [Line Items]
Number of sale-leaseback transactions | transaction	0	1
Aircraft Engine | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	1 month
Aircraft Engine | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	11 years
Aircraft and Aircraft Engines
Lessee, Lease, Description [Line Items]
Gains recognized on sale-leaseback transactions | $	$ 71	$ 40
A320neo
Lessee, Lease, Description [Line Items]
Number of leases in period	0	3
A320neo | Aircraft | Aircraft Sale Leaseback
Lessee, Lease, Description [Line Items]
Number of sale-leaseback transactions | aircraft	6	3