Leases - Other Quantitative Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Leases
Weighted-average remaining lease term		5 years 7 months 6 days	8 years 2 months 12 days
Weighted-average discount rate	[1]	3.60%	5.40%
Finance Leases
Weighted-average remaining lease term		16 years 8 months 12 days	17 years 8 months 12 days
Weighted-average discount rate	[1]	16.20%	16.20%
Operating cash flows from operating leases		$ 483	$ 309	$ 389
Operating cash flows from finance leases		10	10	9
Right-of-use assets obtained in exchange for operating lease liabilities		$ 1,736	$ 615	$ 235

[1] The finance leases commenced prior to the adoption of the current leasing standard under GAAP. In accordance with previous accounting guidance, the implied rate is based on the fair value of the underlying assets.