Summary of Investments - SOI Mortgage provision allowance rollforward (Details 4) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Allowance ending balance by basis of impairment method:
Collectively evaluated for impairment	$ 2,890	$ 2,890
Mortgage Loans on Real Estate
Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:
Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:	3,443,073	3,366,460
Individually evaluated for impairment	12,878	12,986
Collectively evaluated for impairment	3,430,195	3,353,474
Mortgage Loans on Real Estate \| Performing Financing Receivable
Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:
Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:	$ 3,443,073	$ 3,366,460

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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The balance of financing receivables that were collectively evaluated for impairment.

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

-Publisher FASB

-Name Accounting Standards Codification

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The balance of financing receivables that were individually evaluated for impairment.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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-Section 50

-Paragraph 11B

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-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

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

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-Name Accounting Standards Codification

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