Lessee, Lease Expense Components (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Amortization of leasehold interests in land	$ 51	$ 35	$ 37
Operating lease cost	34
Short-term lease cost	19
Variable lease cost	5
Amortization of ROU assets	5
Interest on lease liabilities	1
Total lease cost	$ 115