Inventory (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Inventory Disclosure [Abstract]
Raw materials	$ 779	$ 706
Work-in-process	305	272
Finished goods	872	867
Inventories at FIFO	1,956	1,845
Excess of FIFO over LIFO cost	(155)	(144)
Total inventory	$ 1,801	$ 1,701