Leases - Supplemental Cash Flow and Other Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases	$ 197	$ 188	$ 167
Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases	9	8	7
Cash paid for amounts included in the measurement of lease liabilities: Financing cash flows from finance leases	4	7	9
ROU assets obtained in exchange for new finance lease liabilities	166	22	2
ROU assets obtained in exchange for new operating lease liabilities	$ 143	$ 150	$ 122
Weighted-average remaining lease term: Operating leases	6 years	7 years	6 years
Weighted-average remaining lease term: Finance leases	30 years	19 years	20 years
Weighted-average discount rate: Operating leases	8.10%	9.00%	9.10%
Weighted-average discount rate: Finance leases	6.30%	8.40%	5.60%