Investments Classified by Maturity Date (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value
Total	$ 862,345	$ 762,855
Fixed Maturities
Cost or Amortized Cost
Due in one year or less	73,378
Due after one year through five years	347,550
Due after five years through ten years	149,013
Due after ten years	13,429
Asset and mortgage backed securities	291,075
Cost or adjusted/amortized cost	$ 874,445	763,434
Percent of Total
Due in one year or less	8.40%
Due after one year through five years	39.80%
Due after five years through ten years	17.00%
Due after ten years	1.50%
Asset and mortgage backed securities	33.30%
Total	100.00%
Fair Value
Due in one year or less	$ 73,030
Due after one year through five years	342,999
Due after five years through ten years	145,318
Due after ten years	13,107
Asset or mortgage backed securities	287,891
Total	$ 862,345	$ 762,855
Percent of Total
Due in one year or less	8.50%
Due after one year through five years	39.70%
Due after five years through ten years	16.90%
Due after ten years	1.50%
Asset and mortgage backed securities	33.40%
Total	100.00%