Earnings (Loss) Per Share (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Earnings Per Share [Abstract]
Net Income (Loss) Available to Common Stockholders, Basic	$ 4,347.7	$ 5,069.5	$ 4,328.8
Weighted Average Number of Shares Outstanding, Basic	1,113,923,000	1,105,788,000	1,098,338,000
Earnings Per Share, Basic	$ 3.90	$ 4.58	$ 3.94
Weighted Average Number of Shares Outstanding, Diluted	1,113,967,000	1,105,813,000	1,098,367,000
Weighted Average Number of Shares Outstanding, Common Shares	1,107,112,000	1,099,310,000	1,094,623,000
Incremental Common Shares Attributable to Share-based Payment Arrangements	6,855,000	6,503,000	3,744,000
Weighted Average Number of Shares Outstanding, Diluted, Total	1,113,967,000	1,105,813,000	1,098,367,000
Earnings Per Share, Diluted	$ 3.90	$ 4.58	$ 3.94