Long-term Equity-based Compensation Plans Disclosure of Share-based Compensation Arrangements by Share-based Payment Awards (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options and Stock Appreciation Rights, Outstanding at Beginning of the Year, Number	2,265,711
Options and Stock Appreciation Rights, Outstanding at Beginning of the Year, Weighted Average Exercise Price	$ 39.74
Options and Stock Appreciation Rights, Grants in Period, Gross	265,750
Options and Stock Appreciation Rights, Grants in Period, Weighted Average Exercise Price	$ 36.17
Options and Stock Appreciation Rights, Exercises in Period	(239,250)
Options and Stock Appreciation Rights, Exercises in Period, Weighted Average Exercise Price	$ 28.16
Options and Stock Appreciation Rights, Forfeitures and Expirations in Period	(427,024)
Options and Stock Appreciation Rights, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 46.23
Options and Stock Appreciation Rights, Outstanding at End of the Year, Number	1,865,187
Options and Stock Appreciation Rights, Outstanding at End of the Year, Weighted Average Exercise Price	$ 39.23
Options and Stock Appreciation Rights, Outstanding at End of Period, Weighted Average Remaining Contractual Term	5 years 0 months 29 days
Options and Stock Appreciation Rights, Outstanding at End of Period, Aggregate Intrinsic Value	$ 5.5
Options and Stock Appreciation Rights, Vested and Expected to Vest, Outstanding at End of Period, Number	1,821,284
Options and Stock Appreciation Rights, Vested and Expected to Vest, Outstanding at End of Period, Weighted Average Exercise Price	$ 39.34
Options and Stock Appreciation Rights, Vested and Expected to Vest, Outstanding at End of Period, Weighted Average Remaining Contractual Term	5 years
Options and Stock Appreciation Rights, Vested and Expected to Vest, Outstanding at End of Period, Aggregate Intrinsic Value	5.3
Options and Stock Appreciation Rights, Vested and Expected to Vest, Exercisable at End of Period, Number	1,295,183
Options and Stock Appreciation Rights, Vested and Expected to Vest, Exercisable at End of Period, Weighted Average Exercise Price	$ 40.96
Options and Stock Appreciation Rights, Vested and Expected to Vest, Exercisable at End of Period, Weighted Average Remaining Contractual Term	3 years 4 months 17 days
Options and Stock Appreciation Rights, Vested and Expected to Vest, Exercisable at End of Period, Aggregate Intrinsic Value	3.4
Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 8.06	$ 10.18
Options, Exercises in Period, Total Intrinsic Value	2.3	0.3
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options	0.8	0.1
Proceeds from Stock Options Exercised	$ 1.6	$ 0