Stock-Based Compensation (Details Textual) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Payout Percentage	100.00%
Undistributed performance share units	0.5
Weighted-average grant date fair value of undistributed performance share units	$ 40.31
Undistributed and vested performance share units	0.2
Net stock-based compensation expense	$ 15.2	[1]	$ 13.7	[1]	$ 15.4	[1]
Total unrecognized compensation cost	12.1
Estimated forfeiture rate	20.00%
Maximum [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Potential increase for payout percentage	200.00%
Minimum [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Potential increase for payout percentage	101.00%
Performance Share Units [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Payout Percentage	52.50%		0.00%		127.70%
Net stock-based compensation expense	5.7		1.7		4.1
Weighted average period of recognition	2 years 3 months 24 days
Restricted Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Net stock-based compensation expense	5.0		6.6		6.6
Total unrecognized compensation cost	11.9
Weighted average period of recognition	2 years 3 months 18 days
Estimated forfeiture rate	20.90%
Stock Appreciation Rights [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Net stock-based compensation expense	4.5		5.4		4.7
Total unrecognized compensation cost	$ 9.7
Weighted average period of recognition	2 years 3 months 24 days
Estimated forfeiture rate	19.60%
2010 Incentive Plan [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Number of common stock shares which are authorized to issue awards	24.3
Awards granted - Common stock	20.6
Shares available for future issuance	3.7

[1] Stock-Based Compensation expense is recorded in our Corporate and other business segment.