Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2012	Dec. 31, 2011
Income Tax Examination [Line Items]
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	$ 3.8
Unrecognized tax benefits		0.3	1.1
Amount of accrued interest expense included as a liability within the Company's Condensed Consolidated Statements of Financial Position			0.1
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions		0.8
Recognition of previously reserved tax benefits		$ 0.6