Leases - Maturity Schedules (Details) $ in Millions	Jun. 30, 2019 USD ($)
Operating leases
2019 (excluding the six months ended June 30, 2019)	$ 56
2020	97
2021	75
2022	53
2023	37
Thereafter	57
Total future undiscounted lease payments	375
Less imputed interest	(37)
Total reported lease liability	338
Finance leases
2019 (excluding the six months ended June 30, 2019)	1
2020	1
2021	0
2022	0
2023	0
Thereafter	0
Total future undiscounted lease payments	2
Less imputed interest	0
Total reported lease liability	$ 2