Pension, Savings and Other Postretirement Benefit Plans - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined contribution savings plan, contribution expense recognized	$ 28	$ 30		$ 86	$ 93
Postretirement benefits credit	2	4		5	17
U.S.
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	24
Net curtailments and settlements	24	0		25	0
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Net curtailments and settlements	2	$ 0		2	$ 13
Contributions to pension plans	14			41
Non-U.S. | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to funded pension plans in current year	50			50
Non-U.S. | Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to funded pension plans in current year	75			75
U.K.
Defined Benefit Plan Disclosure [Line Items]
Settlement charge			$ 14
Settlement of benefit obligation			$ 41
Plans Initiated in Prior Years
Defined Benefit Plan Disclosure [Line Items]
Net curtailments and settlements	$ 13			$ 14