Lessee - Supplemental Information Related to Operating Leases (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities - Operating cash flows	$ 29	$ 32	$ 58	$ 64
ROU assets obtained in exchange for new lease liabilities	$ 29	$ 14	$ 56	$ 23
Weighted-average remaining lease term (years)	5 years	4 years	5 years	4 years
Weighted-average discount rate (percent)	5.40%	5.63%	5.40%	5.63%