Employee Benefits - Schedule of changes in level 3 fair value for Other Plans (Details) - Other [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Change in fair value of plan assets
Balance at the beginning of the period	$ 1,161	$ 1,061
Actual return on plan assets:
Foreign currency impact	(133)	(128)
Balance at the end of the period	1,019	1,161
Alternative investments [Member]
Change in fair value of plan assets
Balance at the beginning of the period	8
Actual return on plan assets:
Balance at the end of the period	9	8
Significant Unobservable Inputs (Level 3)
Change in fair value of plan assets
Balance at the beginning of the period	8	25
Actual return on plan assets:
Relating to assets still held at the end of the year	2	1
Relating to assets sold during the year	0	0
Purchases, sales and settlements—net	0	(17)
Transfer in/(out) of Level 3	0	0
Foreign currency impact	(1)	(1)
Balance at the end of the period	9	8
Significant Unobservable Inputs (Level 3) | Pooled funds - Real estate [Member]
Change in fair value of plan assets
Balance at the beginning of the period	0	17
Actual return on plan assets:
Relating to assets still held at the end of the year	0	0
Relating to assets sold during the year	0	0
Purchases, sales and settlements—net	0	(17)
Transfer in/(out) of Level 3	0	0
Foreign currency impact	0	0
Balance at the end of the period	0	0
Significant Unobservable Inputs (Level 3) | Alternative investments [Member]
Change in fair value of plan assets
Balance at the beginning of the period	8	8
Actual return on plan assets:
Relating to assets still held at the end of the year	2	1
Relating to assets sold during the year	0	0
Purchases, sales and settlements—net	0	0
Transfer in/(out) of Level 3	0	0
Foreign currency impact	(1)	(1)
Balance at the end of the period	$ 9	$ 8