Lessee - Supplemental Information Related to Operating Leases (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities - Operating cash flows	$ 31	$ 31	$ 89	$ 95
ROU assets obtained in exchange for new lease liabilities	$ 17	$ 5	$ 73	$ 28
Weighted-average remaining lease term (years)	5 years	4 years	5 years	4 years
Weighted-average discount rate (percent)	5.06%	5.63%	5.06%	5.63%