Leases and Capacity Purchase Agreements - Components of Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Operating lease cost	$ 1,038	$ 1,213	$ 1,433
Variable and short-term lease cost	2,548	2,569	2,209
Amortization of finance lease assets	68	75	77
Interest on finance lease liabilities	85	44	24
Sublease income	(32)	(38)	(36)
Total lease cost	$ 3,707	$ 3,863	$ 3,707

Variable And Short-Term Lease, Cost

No definition available.

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- Definition

Amount of interest expense on finance lease liability.

+ References

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-Publisher FASB
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-Section 50
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- Definition

Amount of amortization expense attributable to right-of-use asset from finance lease.

+ References

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- Definition

Amount of lease cost recognized by lessee for lease contract.

+ References

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- References

No definition available.

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

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- Definition

Amount of sublease income excluding finance and operating lease expense.

+ References

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