Income Taxes (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	9 Months Ended
Jun. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Decrease in gross unrecognized tax benefits due to settlement with the IRS	$ 27.2
Benefit to effective income tax rate from tax settlements		19.7
Gross unrecognized tax benefits		25.0
Unrecognized tax benefits that would impact effective tax rate, if recognized, net of associated tax assets and excluding the federal tax benefit of state taxes, interest and penalties		$ 12.7	$ 32.8

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to domestic income tax settlement.

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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-Glossary Unrecognized Tax Benefit

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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