Inventories (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Inventory, Net [Abstract]
Finished products	$ 4,794	$ 4,645
Semifinished products	2,110	2,576
Raw materials, stores and supplies	1,248	1,360
Total inventories before LIFO adjustment	8,152	8,581
Adjustment of inventories to a last-in, first-out (LIFO) basis	(542)	(539)
Total	$ 7,610	$ 8,042