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Investment Securities (Investments Held on Deposit or as Collateral) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investments, Debt and Equity Securities [Abstract]
Investments held in trusts	$ 169.9	$ 79.2
Assets held by insurance regulators	$ 319.3	$ 313.4

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- Definition

Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 320

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6485772&loc=d3e22002-158495

+ Details

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- Details

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- Definition

Investments Held In Trusts

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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