Pension, Savings and Other Postretirement Benefit Plans - Defined Benefit Pension Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
U.S.
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	$ 1	$ 1
Interest cost	40	42
Expected return on plan assets	(60)	(64)
Amortization of net losses	28	27
Net periodic pension cost	9	6
Non-U.S.
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	7	7
Interest cost	17	20
Expected return on plan assets	(19)	(22)
Amortization of net losses	8	7
Net periodic pension cost	$ 13	$ 12