Pension and Other Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 1	$ 0	$ 1
Interest cost	1	1	3	3
Recognized prior service credit	(9)	(11)	(28)	(31)
Recognized net loss	1	1	3	3
Net periodic cost (benefit)	(7)	(8)	(22)	(24)
Pension Benefits - U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	3	14	10
Interest cost	12	13	35	38
Expected return on plan assets	(22)	(21)	(63)	(62)
Recognized net loss	16	13	40	39
Net periodic cost (benefit)	11	8	26	25
Pension Benefits - Non-U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	6	19	18
Interest cost	19	19	58	57
Expected return on plan assets	(40)	(38)	(120)	(109)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	0	(4)	0	(4)
Recognized prior service credit	(2)	(3)	(8)	(9)
Recognized net loss	11	11	33	32
Net periodic cost (benefit)	$ (7)	$ (9)	$ (18)	$ (15)