Earnings Per Share and Equity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Earnings Per Share And Equity Additional Narrative Information [Abstract]
Stock options not included in the calculation of diluted common shares outstanding									14.00	9.00	8.00
Treasury Stock, Shares held	35.00				35.00				35.00	35.00
Treasury stock, at cost	$ 2,327.00				$ 2,327.00				$ 2,327.00	$ 2,327.00
Earnings Per Share Diluted
Income from continuing operations
Income from discontinued operations
Net income on common stock									$ 1,160.00	$ 2,495.00	$ 2,563.00
Average common shares outstanding - basic	854.00	854.00	853.00	705.00	664.00	663.00	663.00	662.00	816.00	663.00	661.00
Assumed exercise of stock options, performance share awards and restricted stock									3.00	2.00	2.00
Average common shares outstanding - diluted	857.00	857.00	856.00	707.00	666.00	665.00	664.00	664.00	819.00	665.00	663.00