Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Examination [Line Items]
Federal corporate tax rate	35.00%	35.00%	35.00%
Increase in net liability for unrecognized tax benefits	$ 0.5	$ 2.2
Accrued interest expense	0.2	0.4
Unrecognized tax benefits that would impact our effective tax rate	7.4	6.9
Interest included in total liability	3.6	3.4
Significant increases or decreases for uncertain tax positions	0
State and Foreign Tax Authorities \| Minimum
Income Tax Examination [Line Items]
Period of statute of limitations (years)	3 years
State and Foreign Tax Authorities \| Maximum
Income Tax Examination [Line Items]
Period of statute of limitations (years)	4 years
IRS
Income Tax Examination [Line Items]
Estimated interest charges for unfavorable outcome	$ 2.1

The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems.

+ References+ Details

This element represents the amount of interest expense accrued as of the date of the statement of financial position for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity.

+ References+ Details

- Definition

This element represents interest expense recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity.

+ References+ Details