Investments (Mortgage Loans by Method of Evaluation and Related Valuation Allowances) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Mortgage Loans [Abstract]
Financing Receivable, Individually Evaluated for Impairment	$ 17,027	$ 37,841
Financing Receivable, Collectively Evaluated for Impairment	2,701,682	2,458,945
Loans Receivable, Gross, Commercial, Real Estate	2,718,709	2,496,786
Valuation Allowances [Abstract]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	816	3,211
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	5,655	6,895
Allowance for Loan and Lease Losses, Real Estate	6,471	10,106	11,580	11,793
Mortgage Loans Net Of Valuation Allowance [Abstract]
Mortgage loans on real estate	$ 2,712,238	$ 2,486,680

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The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

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

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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

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

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Amount before allowance of commercial loans issued to businesses to acquire, develop, construct, improve, or refinance land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

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