Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Property, plant and equipment, accumulated depreciation	$ 10,855	$ 10,497
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	800,000,000	800,000,000
Common stock, issued	382,911,932	382,854,272
Treasury stock, shares	84,222,591	84,324,255