Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Attributable to Parent	$ 1,047	$ 549	$ 1,003	$ 429
Weighted Average Number of Shares Outstanding, Basic	846	838	845	838
Incremental Common Shares Attributable to Share-based Payment Arrangements	4	6	4	6
Weighted Average Number of Shares Outstanding, Diluted	850	844	849	844
Earnings Per Share, Basic	$ 1.24	$ 0.66	$ 1.19	$ 0.51
Earnings Per Share, Diluted	$ 1.23	$ 0.65	$ 1.18	$ 0.51
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	19	26	19	25