Lease Liabilities Maturities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Maturity of Lease Liabilities, Operating Leases [Abstract]
Remainder of 2019	$ 10
2019		$ 61
2020	60	53
2021	47	40
2022	39	33
2023	32	26
Thereafter	80	65
Total lease payments	268
Less: Interest	(25)
Total	$ 243	$ 278
Operating lease, Weighted-average remaining lease term (years)	6 years 1 month 6 days
Operating lease, Weighted-average discount rate, percent	3.10%
Maturity of Lease Liabilities - Finance Leases [Abstract]
Remainder of 2019	$ 4
2020	14
2021	10
2022	10
2023	10
Thereafter	19
Total lease payments	67
Less: Interest	(6)
Total	$ 61
Finance lease, Weighted-average remaining lease term	6 years 1 month 6 days
Finance lease, Weighted-average discount rate, percent	3.40%