Issuer and counterparty credit exposure Narrative (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013 counterparty	Dec. 31, 2012
Concentration Risk [Line Items]
Fixed maturities below-investment-grade assets	$ 137.7	$ 182.5
Derivative assets, net of liabilities	127.0
Number of counterparties	11
Debt securities, fair value	43.6
Maximum amount of loss due to credit risk	$ 170.6
Stockholders' Equity
Concentration Risk [Line Items]
Reinsurance recoverable percentage	10.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

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-URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13537-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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