Postretirement Benefit Plans - Changes in Fair Values for Level 3 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
U.S. defined benefit plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 1,082	$ 941
Fair value of plan assets at end of year (FVPA)	1,019	1,082
U.S. defined benefit plan | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	37
Redemptions and sales	0	(45)
Unrealized gain (loss)		8
Fair value of plan assets at end of year (FVPA)	0	0
Non-U.S. defined benefit plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	2,213	2,179
Fair value of plan assets at end of year (FVPA)	2,134	2,213
Non-U.S. defined benefit plan | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	5	8
Redemptions and sales	(1)	(2)
Unrealized gain (loss)		(1)
Fair value of plan assets at end of year (FVPA)	$ 4	$ 5