Income Taxes - Narrative (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred Tax Liability Not Recognized [Line Items]
Income Taxes Paid	$ 52.2	$ 57.1	$ 65.1
Proceeds from Income Tax Refunds		4.1
Unrecognized Tax Benefits, Interest on Income Taxes Expense	(0.4)	0.4	0.7
Mutual Savings Life [Member] \| Undistributed Domestic Earnings [Member]
Deferred Tax Liability Not Recognized [Line Items]
Deferred Tax Liability Not Recognized, Cumulative Amount of Temporary Difference	14.7
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability	$ 5.1

The amount of the deferred tax liability which was not recognized because of the exceptions to comprehensive recognition of deferred taxes.

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The cumulative amount of the temporary difference for which a deferred tax liability has not been provided because of the exceptions to comprehensive recognition of deferred taxes.

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- Definition

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

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- 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.

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