Leases - Other Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating cash flows for operating leases	$ 108	$ 116
Operating cash flows for finance leases	5	1
Financing cash flows for finance leases	19	18
Non-cash change in lease liabilities arising from obtaining new right of use assets or modifications, operating leases	5	77
Non-cash change in lease liabilities arising from obtaining new right of use assets or modifications, finance leases	$ 32	$ 27
Weighted-average remaining lease term (in years):
Operating lease, weighted-average lease term	12 years	11 years
Finance lease, weighted-average lease term	9 years	6 years
Weighted-average discount rate:
Operating lease, weighted-average discount rate	4.50%	4.40%
Finance lease, weighted-average discount rate	11.10%	7.10%
Equity Method Investees | Agreement to store at facilities owned by equity method investee
Lessee, Lease, Description [Line Items]
Non-cash change in lease liabilities arising from obtaining new right of use assets or modifications, finance leases	$ 25	$ 12
Ownership interest in unconsolidated entity	50.00%