Employee Benefits Schedule of changes in Level 3 fair value for U.S. Pension Plans (Details) (U.S. [Member], USD $) In Millions, unless otherwise specified				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Significant Unobservable Inputs (Level 3) [Member]	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) [Member]
Change in fair value of plan assets
Balance at the beginning of the period	$ 1,855	$ 1,631	$ 1,325	$ 262	$ 191
Actual return on plan assets:
Relating to assets still held at the end of the year				26	22
Relating to assets sold during the year				4	1
Purchases, sales and settlements—net				(26)	48
Transfer in/(out) of Level 3				0	0
Balance at the end of the period	$ 1,855	$ 1,631	$ 1,325	$ 266	$ 262