Investments (Details 10) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Commercial mortgage loans
Net commercial mortgage loans	$ 420,569	$ 499,814
70% and less \| Maximum
Commercial mortgage loans
Loan-to-value percentage	70.00%	70.00%
71 - 80% \| Minimum
Commercial mortgage loans
Loan-to-value percentage	71.00%	71.00%
71 - 80% \| Maximum
Commercial mortgage loans
Loan-to-value percentage	80.00%	80.00%
81 - 95% \| Minimum
Commercial mortgage loans
Loan-to-value percentage	81.00%	81.00%
81 - 95% \| Maximum
Commercial mortgage loans
Loan-to-value percentage	95.00%	95.00%
Greater than 95% \| Minimum
Commercial mortgage loans
Loan-to-value percentage	95.00%	95.00%
Commercial mortgage loans
Commercial mortgage loans
Commercial mortgage loans	$ 421,643	$ 501,278
Less valuation allowance	(1,074)	(1,464)
Net commercial mortgage loans	$ 420,569	$ 499,814
% of Gross Mortgage Loans (as a percent)	100.00%	100.00%
Debt-Service Coverage Ratio	1.96	1.90
Commercial mortgage loans \| Minimum
Commercial mortgage loans
Commercial mortgage loans	$ 122	$ 77
Commercial mortgage loans \| Maximum
Commercial mortgage loans
Commercial mortgage loans	11,966	12,251
Commercial mortgage loans \| 70% and less
Commercial mortgage loans
Commercial mortgage loans	$ 399,321	$ 447,941
% of Gross Mortgage Loans (as a percent)	94.70%	89.40%
Debt-Service Coverage Ratio	1.98	1.99
Commercial mortgage loans \| 71 - 80%
Commercial mortgage loans
Commercial mortgage loans	$ 11,590	$ 40,651
% of Gross Mortgage Loans (as a percent)	2.80%	8.10%
Debt-Service Coverage Ratio	1.25	1.28
Commercial mortgage loans \| 81 - 95%
Commercial mortgage loans
Commercial mortgage loans	$ 5,916	$ 6,155
% of Gross Mortgage Loans (as a percent)	1.40%	1.20%
Debt-Service Coverage Ratio	0.92	0.99
Commercial mortgage loans \| Greater than 95%
Commercial mortgage loans
Commercial mortgage loans	$ 4,816	$ 6,531
% of Gross Mortgage Loans (as a percent)	1.10%	1.30%
Debt-Service Coverage Ratio	3.52	0.43
Commercial mortgage loans \| Investment portfolio \| Geographic concentration risk \| California, New York and Utah
Commercial mortgage loans
Concentration percentage	39.00%

Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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