Adoption of New Leasing Standard - Lessee - Supplemental Information Related to Operating Leases (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)		Sep. 30, 2019 USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities - Operating cash flows	$ 31		$ 95
Right-of-use assets obtained in exchange for new lease liabilities	$ 5	[1]	$ 28	[1]
Weighted-average remaining lease term	4 years		4 years
Weighted-average discount rate	5.63%		5.63%

[1] Includes the impact of new leases as well as remeasurements and modifications to existing leases.