Investments Fixed Maturities by Contractual Maturity Periods (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Due In One Year or Less, Amortized Cost	$ 5,138
Due In One Year or Less, Fair Value	5,117
Due After One Year Through Five Years, Amortized Cost	4,937
Due After One Year Through Five Years, Fair Value	4,781
Due After Five Year Through Ten Years, Amortized Cost	125
Due After Five Year Through Ten Years, Fair Value	117
Due After Ten Years, Amortized Cost	1,116
Due After Ten Years, Fair Value	1,061
Fixed maturities, cost	11,316	$ 14,707
Estimated Fair Value, Fixed Maturities	$ 11,076	$ 14,541