Long-term Equity-based Compensation - Option and SAR Activity (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Options at Beginning of Year	3,632,398
Weighted Average Exercise Price Per Share at Beginning of Year	$ 40.70
Grants in Period	265,451
Grants in Period, Weighted Average Exercise Price	$ 29.81
Exercises in Period	(222,949)
Exercises in Period, Weighted Average Exercise Price	$ 16.32
Forfeitures and Expirations in Period	(482,846)
Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 47.10
Shares Subject to Options at End of Year	3,192,054	3,632,398
Weighted Average Exercise Price Per Share at End of Year	$ 40.53	$ 40.70
Outstanding at End of Year, Weighted Average Remaining Contractual Term	3 years 11 months 19 days
Outstanding at End of Year, Intrinsic Value	$ 3.0
Vested and Expected to Vest, Outstanding at End of Year	3,162,634
Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 40.64
Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	3 years 11 months 5 days
Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	2.9
Vested and Expected to Vest, Exercisable at End of Year	2,736,989
Vested and Expected to Vest, Exercisable at End of Year, Weighted Average Exercise Price	$ 42.69
Vested and Expected to Vest, Exercisable at End of Year, Weighted Average Remaining Contractual Term	3 years 2 months 27 days
Vested and Expected to Vest, Exercisable at End of Year, Aggregate Intrinsic Value	2.0
Option Grants in Period, Weighted Average Grant Date Fair Value	$ 9.40	$ 9.11	$ 7.60
Option Exercises in Period, Total Intrinsic Value	3.0	0.3	0.3
Proceeds from Stock Options Exercised	1.3	0.2	0.5
Tax Benefit from Stock Options Exercised	$ 1.0	$ 0.1	$ 0.1