Pension, Savings and Other Postretirement Benefit Plans - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined contribution savings plan, contribution expense recognized	$ 28	$ 29	$ 58	$ 63
Postretirement benefits credit	1	7	3	$ 13
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Contributions to pension plans	13		27
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 of benefit obligation		41
Settlement charge		$ 14