Pension and Other Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0
Interest cost	1	1
Recognized prior service credit	(9)	(10)
Recognized net loss	1	1
Net periodic cost (benefit)	(7)	(8)
Pension Benefits - U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	3
Interest cost	12	12
Expected return on plan assets	(21)	(20)
Recognized net loss	12	13
Net periodic cost (benefit)	7	8
Pension Benefits - Non-U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	6
Interest cost	19	19
Expected return on plan assets	(40)	(35)
Recognized prior service credit	(3)	(3)
Recognized net loss	11	10
Net periodic cost (benefit)	$ (6)	$ (3)