Fair Values Valuation of Financial Instruments not reported at fair value (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financial Instruments Not Reported at Fair Value [Line Items]
Mortgage loans	$ 1,019,124	$ 1,039,829
Policy loans	200,246	197,366
Other investments	48,833	33,765
Other investments	21,198	5,757
Deposit Contracts, Liabilities	302,685	303,627
Liabilities related to separate accounts	625,177	561,281
Portion at Other than Fair Value Measurement | Fair Value, Measurements, Recurring
Financial Instruments Not Reported at Fair Value [Line Items]
Mortgage loans	1,061,562	1,045,497
Policy loans	253,802	237,496
Other investments	29,934	30,087
Total assets	1,345,298	1,313,080
Future policy benefits	4,255,017	3,981,947
Supplemental contracts without life contingencies, fair value disclosure	311,443	298,869
Advance premiums and other deposits	250,601	252,318
Long-term debt	78,182	65,999
Liabilities related to separate accounts	623,839	559,799
Total liabilities	5,519,082	5,158,932
Reported Value Measurement
Financial Instruments Not Reported at Fair Value [Line Items]
Mortgage loans	1,019,124	1,039,829
Policy loans	200,246	197,366
Other investments	29,135	29,020
Total assets	1,248,505	1,266,215
Future policy benefits	4,237,938	4,217,904
Deposit Contracts, Liabilities	302,685	303,627
Advance premiums and other deposits	250,601	252,318
Long-term debt	97,000	97,000
Liabilities related to separate accounts		561,281
Total liabilities	5,513,401	5,432,130
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Financial Instruments Not Reported at Fair Value [Line Items]
Other investments	0	0
Future policy benefits	0	0
Fair Value, Inputs, Level 1 | Portion at Other than Fair Value Measurement | Fair Value, Measurements, Recurring
Financial Instruments Not Reported at Fair Value [Line Items]
Mortgage loans	0	0
Policy loans	0	0
Other investments	0	0
Total assets	0	0
Future policy benefits	0	0
Supplemental contracts without life contingencies, fair value disclosure	0	0
Advance premiums and other deposits	0	0
Long-term debt	0	0
Liabilities related to separate accounts	0	0
Total liabilities	0	0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Financial Instruments Not Reported at Fair Value [Line Items]
Other investments	19,698	4,745
Future policy benefits	0	0
Fair Value, Inputs, Level 2 | Portion at Other than Fair Value Measurement | Fair Value, Measurements, Recurring
Financial Instruments Not Reported at Fair Value [Line Items]
Mortgage loans	0	0
Policy loans	0	0
Other investments	0	0
Total assets	0	0
Future policy benefits	0	0
Supplemental contracts without life contingencies, fair value disclosure	0	0
Advance premiums and other deposits	0	0
Long-term debt	0	0
Liabilities related to separate accounts	0	0
Total liabilities	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Financial Instruments Not Reported at Fair Value [Line Items]
Other investments	0	0
Fair Value, Inputs, Level 3 | Portion at Other than Fair Value Measurement | Fair Value, Measurements, Recurring
Financial Instruments Not Reported at Fair Value [Line Items]
Mortgage loans	1,061,562	1,045,497
Policy loans	253,802	237,496
Other investments	29,934	30,087
Total assets	1,345,298	1,313,080
Future policy benefits	4,255,017	3,981,947
Supplemental contracts without life contingencies, fair value disclosure	311,443	298,869
Advance premiums and other deposits	250,601	252,318
Long-term debt	78,182	65,999
Liabilities related to separate accounts	623,839	559,799
Total liabilities	$ 5,519,082	$ 5,158,932