Long-term Equity-based Compensation Plans - Fair Value Assumptions (Details) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Options, Outstanding, Weighted Average Remaining Contractual Term	4
Options, Outstanding, Intrinsic Value	$ 2.4
Options, Vested and Expected to Vest, Outstanding, Number	3,778,505
Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 9.11	$ 7.70
Options, Exercised in Period, Total Intrinsic Value	0.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Outstanding at Beginning of the Year	4,004,546
Options, Outstanding, Weighted Average Exercise Price, Beginning of the Year	$ 42.34
Options, Granted in Period	313,750
Options, Granted in Period, Weighted Average Exercise Price	$ 28.10
Options, Exercised in Period	(12,000)
Options, Exercised in Period, Weighted Average Exercise Price	$ 19.43
Options, Forfeited and Expired in Period	(498,494)
Options, Forfeited and Expired in Period, Weighted Average Exercise Price	$ 46.45
Options, Outstanding at End of the Period	3,807,802
Options, Outstanding, Weighted Average Exercise Price, End of the Year	$ 40.70
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract]
Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	4
Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	2.4
Options, Vested and Expected to Vest, Exercised, Number	3,312,613
Options, Vested and Expected to Vest, Exercised, Weighted Average Exercise Price	$ 43.07
Options, Vested and Expected to Vest, Exercised, Weighted Average Remaining Contractual Term	4
Options, Vested and Expected to Vest, Exercised, Aggregate Intrinsic Value	1.8
Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 40.82
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	9,907,950
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Restricted Stock, Nonvested Balance at Beginning of the Year	218,156
Restricted Stock, Nonvested Balance at Beginning of the Year	$ 23.72
Nonvested Restricted Stock, Granted in Period	135,425
Nonvested Restricted Stock, Granted in Period, Weighted Average Grant Date Fair Value	$ 32.61
Nonvested Restricted Stock, Vested in Period	(50,821)
Nonvested Restricted Stock, Vested in Period, Weighted Average Grant Date Fair Value	$ 30.18
Nonvested Restricted Stock, Forfeited in Period	(907)
Nonvested Restricted Stock, Forfeited in Period, Weighted Average Grant Date Fair Value	$ 25.60
Restricted Stock, Nonvested Balance at End of the Period	301,853
Restrited Stock, Nonvested Balance at End of the Period	$ 26.62
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value	1.4	2.2
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	$ 0.5	$ 0.8
Time Vested Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested Restricted Stock, Granted in Period	69,950
Restricted Stock, Nonvested Balance at End of the Period	125,778
Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested Restricted Stock, Granted in Period	65,475
Restricted Stock, Nonvested Balance at End of the Period	176,075