Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 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	19.8
Gross unrecognized tax benefits	25.0	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	$ 12.0	$ 12.0	$ 32.8

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to domestic income tax settlements for the period.

+ References

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- Definition

The gross amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

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The gross amount of decreases 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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