Financial Schedules Schedule IV - Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Life Insurance Assumed Ratio	0.10%	0.50%	0.80%
Direct Premiums, Life Insurance in Force	$ 4,967,856	$ 4,997,641	$ 4,958,369
Ceded Premiums, Life Insurance in Force	503,685	522,821	516,933
Assumed Premiums, Life Insurance in Force	5,564	22,915	36,766
Premiums, Net, Life Insurance in Force	4,469,735	4,497,735	4,478,202
Direct Premiums Earned	200,711	201,074	197,337
Ceded Premiums Earned	3,133	3,349	3,210
Assumed Premiums Earned	142	151	353
Premiums Earned, Net	$ 197,720	$ 197,876	$ 194,480
Contracts in Force Subject to Participation through Reinsurance, Ratio	0.10%	0.10%	0.20%
Life Insurance Segment [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	$ 193,534	$ 193,604	$ 189,644
Ceded Premiums Earned	2,334	2,501	2,311
Assumed Premiums Earned	142	151	353
Premiums Earned, Net	191,342	191,254	187,686
Accident and Health Insurance Segment [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	1,410	1,566	1,625
Ceded Premiums Earned	18	20	26
Assumed Premiums Earned	0	0	0
Premiums Earned, Net	1,392	1,546	1,599
Property, Liability and Casualty Insurance Segment [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	5,767	5,904	6,068
Ceded Premiums Earned	781	828	873
Assumed Premiums Earned	0	0	0
Premiums Earned, Net	$ 4,986	$ 5,076	$ 5,195