Incentive Stock Plans Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Share Units (Details) (Performance Share Units [Member], USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y		Dec. 31, 2010		Dec. 31, 2009
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Description	Based on the 3-year U.S. treasury rate on the date of the award
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	three-year period
Number of Common Shares of Company Stock Reserved for Issuance Under Incentive Stock Plans	470,820		606,180		916,362
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	1,030,075		1,150,532
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 33.73		$ 29.74
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	51.30%		51.70%		43.60%
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 11.4
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 51.57		$ 39.25		$ 21.76
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Aggregate Instrinsic Value	46.0	[1]	40.3	[1]	34.3	[1]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	1.3
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Method Used	Monte Carlo simulation model
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Aggregate Intrinsic Value	46.0	[1]	40.3	[1]	34.3	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value	9.9		19.7		16.0
Payments Related to Tax Withholding for Share-based Compensation	$ 7.1		$ 5.3		$ 1.4
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate					6.40%	[2]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	1.00%	[3]	1.40%	[3]	1.10%	[3]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	235,410
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(358,737)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 32.64
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Cancellations and Adjustments in Period	2,870
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Cancellations and Adjustments in Period, Weighted Average Grant Date Fair Value	$ 32.64

[1] Intrinsic value of outstanding performance share units is based on the market price of the Company's stock at December 31, 2011.

[2] The 2011 and 2010 awards receive dividend equivalents, so the dividend yield was not used to calculate the fair value.

[3]