Leases - Schedule of Cash Paid for Lease Liabilities and Right-of-Use Assets Obtained in Exchange for Lease Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating cash flows from operating leases	$ 212	$ 210
Operating cash flows from finance leases	1	1
Financing cash flows from finance leases	2	4
Operating leases	227	219
Finance leases	$ 4	$ 1