Employee Benefit Plans - Pension Plan (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
U.S. Pension Benefits
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net service cost	$ 0	$ 0
Interest cost	16	15
Expected return on plan assets	(10)	(11)
Net periodic benefit cost (income)	6	4
International Pension Benefits
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net service cost	2	2
Interest cost	5	5
Expected return on plan assets	(8)	(8)
Net periodic benefit cost (income)	(1)	(1)
Total Pension Benefits
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net service cost	2	2
Interest cost	21	20
Expected return on plan assets	(18)	(19)
Net periodic benefit cost (income)	$ 5	$ 3