Investments (Commercial Mortgage and Other Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 1,080,864	$ 1,652,476
Total commercial mortgage and other loans	$ 1,079,639	$ 1,658,235
% of Total	100.00%	100.00%
Allowance for Doubtful Accounts, Premiums and Other Receivables	$ 1,225	$ 2,651
Total net commercial mortgage and agricultural property loans by property type	1,079,639	1,649,825
Allowance for Loan and Lease Losses, Real Estate	0	0
Total Net Other Loans	0	8,410
Total commercial mortgage loans
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 1,017,075	$ 1,545,853
% of Total	94.10%	93.50%
Uncollateralized loans
Servicing Assets at Fair Value [Line Items]
Uncollateralized Loans	$ 0	$ 8,410
Retail
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 244,537	$ 440,767
% of Total	22.60%	26.70%
Apartments/Multi-Family
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 312,484	$ 445,379
% of Total	28.90%	27.00%
Industrial
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 151,155	$ 254,884
% of Total	14.00%	15.40%
Office
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 142,692	$ 226,332
% of Total	13.20%	13.60%
Other Commercial Loans
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 115,626	$ 92,581
% of Total	10.70%	5.60%
Hospitality
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 50,581	$ 85,910
% of Total	4.70%	5.20%
Agricultural property loans
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 63,789	$ 106,623
% of Total	5.90%	6.50%

Commercial Mortgage Loan,Concentration Percentage

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Loans Receivable, Net, Commercial, Mortgage

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Total Commercial Mortgage And Other Loans

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Total Net Other Loans

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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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Amount before allowance of consumer real estate loans. Includes, but not limited to, construction financing, residential mortgage loans, and home equity lines of credit. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of mortgage loans on existing 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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