Investments - Investments Classified by Contractual Maturity Date (Details) - Fixed Maturities - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Cost or Amortized Cost
Due in one year or less	$ 33,218
Due after one year through five years	250,847
Due after five years through ten years	131,831
Due after ten years	48,211
Cost or adjusted/amortized cost	$ 464,107	$ 396,415
Percent of Total
Due in one year or less	7.20%
Due after one year through five years	54.00%
Due after five years through ten years	28.40%
Due after ten years	10.40%
Total	100.00%
Fair Value
Due in one year or less	$ 33,232
Due after one year through five years	253,958
Due after five years through ten years	135,305
Due after ten years	50,173
Total	$ 472,668	$ 396,698
Percent of Total
Due in one year or less	7.00%
Due after one year through five years	53.70%
Due after five years through ten years	28.60%
Due after ten years	10.70%
Total	100.00%