Postretirement Benefits (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Defined contribution plans
Costs related to defined contribution plans	$ 90	$ 77	$ 265	$ 242
U.S. Plans
Defined contribution plans
Costs related to defined contribution plans	74	62	218	196
Non-U.S. Plans
Defined contribution plans
Costs related to defined contribution plans	$ 16	$ 15	$ 47	$ 46