Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 18,892	$ 19,349
Common stock, par value	$ 0.30	$ 0.30
Common stock, shares authorized	1,800,000	1,800,000
Common stock, shares issued	1,019,411	1,013,164
Common stock held in treasury, shares	87,041	87,041