Operating Leases - Lessor Concessions (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Lessee, Lease, Description [Line Items]
Increase (decrease) in deferrals related to leases		$ (11)
Deferred costs, leasing,	$ 11
Aircraft Rental
Lessee, Lease, Description [Line Items]
Deferrals related to leases	$ 0	(19)
Station Operations
Lessee, Lease, Description [Line Items]
Deferrals related to leases		$ 8

This element represents costs incurred by the lessor that are (a) costs to originate a lease incurred in transactions with independent third parties that (i) result directly from and are essential to acquire that lease and (ii) would not have been incurred had that leasing transaction not occurred and (b) certain costs directly related to specified activities performed by the lessor for that lease. Those activities are: evaluating the prospective lessee's financial condition; evaluating and recording guarantees, collateral, and other security arrangements; negotiating lease terms; preparing and processing lease documents; and closing the transaction. This element is net of accumulated amortization.

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Name:	us-gaap_DeferredCostsLeasingNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant