Policy Liabilities and Short Duration Contracts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Policy claims payable at January 1	$ 9,538	$ 9,653	$ 9,560
Reinsurance recoverable	407	543	950
Net balance policy claims payable at January 1	9,131	9,110	8,610
Claims incurred related to current year	25,036	26,000	26,911
Claims incurred related to prior years	(209)	(493)	(197)
Total claims incurred	24,827	25,507	26,714
Claims paid related to current year	18,037	18,681	19,584
Claims paid related to prior years	7,678	6,805	6,630
Total claims paid	25,715	25,486	26,214
Policy claims payable at December 31	8,610	9,538	9,653
Reinsurance recoverable	(367)	(407)	(543)
Net balance policy claims payable at December 31	$ 8,243	$ 9,131	$ 9,110