Investments (Commercial Mortgage and Other Loans) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Commercial mortgage loans	$ 363,630	$ 366,192
Commercial mortgage loans, Percentage	87.50%	87.10%
Valuation allowance	(407)	(482)
Total net commercial and agricultural mortgage loans by property type	415,342	419,823
Total commercial mortgage and other loans, net of valuation allowance	418,082	422,563
Total Commercial Mortgage By Propterty Type	415,749	420,305
Other Loans and Leases Receivable	2,740	2,740
Valuation Allowance - Other	0	0
Office buildings [Member]
Commercial mortgage loans	44,076	44,621
Commercial mortgage loans, Percentage	10.60%	10.60%
Retail stores [Member]
Commercial mortgage loans	72,718	72,226
Commercial mortgage loans, Percentage	17.50%	17.20%
Apartment Complexes [Member]
Commercial mortgage loans	140,965	143,057
Commercial mortgage loans, Percentage	33.90%	34.00%
Industrial Buildings [Member]
Commercial mortgage loans	86,758	87,088
Commercial mortgage loans, Percentage	20.90%	20.70%
Agricultural Properties [Member]
Commercial mortgage loans	52,119	54,113
Commercial mortgage loans, Percentage	12.50%	12.90%
Hospitality [Member]
Commercial mortgage loans	5,052	5,081
Commercial mortgage loans, Percentage	1.20%	1.20%
Other [Member]
Commercial mortgage loans	14,061	14,119
Commercial mortgage loans, Percentage	3.40%	3.40%
California [Member]
Commercial mortgage loans, Percentage	18.00%
Total Percentage [Member]
Commercial mortgage loans, Percentage	100.00%	100.00%
Uncollateralized Loans [Member]
Other Loans and Leases Receivable	$ 2,740	$ 2,740
Texas [Member]
Commercial mortgage loans, Percentage	12.00%