Investments - Impaired Loans (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014 loan	Dec. 31, 2013 loan
Investments, Debt and Equity Securities [Abstract]
Impaired loans with allowances for losses	$ 0	$ 0
Impaired loans without valuation allowances	94.2	94.3
Subtotal	94.2	94.3
Less: Allowances for losses on impaired loans	0	0
Impaired loans, net	94.2	94.3
Unpaid principal balance of impaired loans	96.6	96.7
Number of loans in arrears	0	1
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	$ 0	$ 5.1

Impaired Financing Receivable, Recorded Investment, Net of Allowance

No definition available.

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- Definition

Impaired Financing Receivable, Unpaid Principal Balance, Number of Loans in Arrears

+ References

No definition available.

+ Details

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- Definition

Financing receivables that are equal to or greater than 90 days past due.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7A

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953401-111524

+ Details

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- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953550-111524

+ Details

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- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524

+ Details

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- Definition

Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (a)(4)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524

+ Details

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- Definition

Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

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- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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