Inventories (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
LIFO method related items [Abstract]
LIFO inventory amount	$ 139	$ 160
Inventory, LIFO reserve	41	36
Inventory, net [Abstract]
Finished products and parts	2,264	1,801
Raw materials and supplies	793	673
Work in process	129	96
Total	3,186	2,570
Obsolescence reserves	$ 114	$ 108