Earnings 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]
Stock options outstanding, antidilutive	3,797,548		4,526,442		7,401,350
Net income (loss)	$ (1,319)		$ 53		$ 634
Net income (loss) available to common shareholders	$ (1,319)		$ 53		$ 623
Basic weighted-average shares	197,019,968	[1]	202,421,433	[1]	208,156,622	[1]
Effect of common stock equivalents: Stock options			599,701
Diluted weighted-average shares	197,019,968		203,021,134		208,156,622
Basic EPS: Net income (loss)	$ (6.69)		$ 0.26		$ 2.99
Diluted EPS: Net income (loss)	$ (6.69)		$ 0.26		$ 2.99
Unvested restricted stock and units that receive nonforfeitable dividends or dividend equivalents	5,080,742		5,325,428		5,259,561

[1] Includes 5,080,742, 5,325,428 and 5,259,561 of unvested restricted stock and units that receive nonforfeitable dividends or dividend equivalents for the years ended December 31, 2011, 2010 and 2009, respectively.