Share-Based Compensation (Details 2) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Share-based Compensation, Stock Options, Activity
Granted	1,500,000	700,000	600,000
Exercised	(200,000)	(300,000)	(1,500,000)
Stock Options [Member]
Schedule of Share-based Compensation, Stock Options, Activity
Options outstanding, Beginning Balance	1,884,780
Granted	369,782
Exercised	(218,281)
Forfeited	(211,056)
Options outstanding, Ending Balance	1,825,225
Options Vested and Exercisable	1,325,951
Weighted Average Exercise Price, Beginning of Period	37.92
Weighted Average Exercise Price, Granted	36.27
Weighted Average Exercise Price, Exercised	9.90
Weighted Average Exercise Price, Forfeited	47.37
Weighted Average Exercise Price, End of Period	39.85
Options Vested and Exercisable, Weighted Average Exercise Price	37.90
Weighted Average Remaining Contractual Life, Beginning of Period	5.6
Options Vested and Exercisable, Weighted Average Remaining Contractual Life	4.6
Aggregate Intrinsic Value, Beginning of Period	11.0
Options Vested and Exercisable, Aggregate Intrinsic Value	2.5