Inventory (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Inventory Disclosure [Abstract]
Raw materials	$ 747	$ 706
Work-in-process	291	272
Finished goods	890	867
Inventories at FIFO	1,928	1,845
Excess of FIFO over LIFO cost	(149)	(144)
Total inventory	$ 1,779	$ 1,701