Investments (Commercial Mortgage and Other Loans) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 401,815	$ 420,305
Valuation allowance	(471)	(482)
Total net commercial mortgage and agricultural property loans by property type	401,344	419,823
Valuation allowance	0	0
Total net other loans	2,740	2,740
Total commercial mortgage and other loans	$ 404,084	$ 422,563
% of Total	100.00%	100.00%
Total commercial mortgage loans
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 350,715	$ 366,192
% of Total	87.30%	87.10%
Uncollateralized loans
Servicing Assets at Fair Value [Line Items]
Other Loans	$ 2,740	$ 2,740
Apartments/Multi-Family
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 140,101	$ 143,057
% of Total	34.90%	34.00%
Industrial
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 50,496	$ 87,088
% of Total	12.60%	20.70%
Retail
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 62,737	$ 72,226
% of Total	15.60%	17.20%
Office
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 78,694	$ 44,621
% of Total	19.60%	10.60%
Other
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 13,693	$ 14,119
% of Total	3.40%	3.40%
Hospitality
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 4,994	$ 5,081
% of Total	1.20%	1.20%
Agricultural property loans
Servicing Assets at Fair Value [Line Items]
Commercial mortgage and agricultural property loans by property type:	$ 51,100	$ 54,113
% of Total	12.70%	12.90%