Income per Common Share (Details) (USD $) In Millions, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Income Per Common Share Note Details [Abstract]
Income loss from continuing operations	$ 405	$ 467	$ 1,158	$ 1,458
Discontinued operations	0	229	1,239	404
Net income	$ 405	$ 696	$ 2,397	$ 1,862
Weighted average number of shares outstanding, basic	711	710	712	709
Effect of dilutive securities	3	2	4	2
Weighted Average Number Of Diluted Shares	714	712	716	711
Basic:
Income from continuing operations, per basic share	$ 0.57	$ 0.66	$ 1.63	$ 2.06
Discontinued operations, per basic share	$ 0.00	$ 0.32	$ 1.74	$ 0.57
Net income, per basic share	$ 0.57	$ 0.98	$ 3.37	$ 2.63
Diluted:
Income from continuing operations, per diluted share	$ 0.57	$ 0.66	$ 1.62	$ 2.05
Discontinued operations, per diluted share	$ 0.00	$ 0.32	$ 1.73	$ 0.57
Net income, per diluted share	$ 0.57	$ 0.98	$ 3.35	$ 2.62
Antidilutive securities excluded from computation of earnings per share	9	12	7	12