Lease Liabilities Maturities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Maturity of Lease Liabilities, Operating Leases [Abstract]
Remainder of 2019	$ 27
2019		$ 61
2020	59	53
2021	45	40
2022	37	33
2023	30	26
Thereafter	75	65
Total lease payments	273
Less: Interest	(27)
Total	$ 246	$ 278
Operating lease, Weighted-average remaining lease term (years)	6 years 3 months 18 days
Operating lease, Weighted-average discount rate, percent	3.10%
Maturity of Lease Liabilities - Finance Leases [Abstract]
Remainder of 2019	$ 8
2020	14
2021	10
2022	10
2023	10
Thereafter	19
Total lease payments	71
Less: Interest	(7)
Total	$ 64
Finance lease, Weighted-average remaining lease term	6 years 3 months 18 days
Finance lease, Weighted-average discount rate, percent	3.40%