Investments - Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value
Total	$ 873,786	$ 884,861
Fixed Maturities
Cost or Amortized Cost
Due in one year or less	81,916
Due after one year through five years	266,843
Due after five years through ten years	194,258
Due after ten years	11,844
Asset and mortgage backed securities	307,704
Cost or adjusted/amortized cost	$ 862,565	869,598
Percent of Total
Due in one year or less	9.50%
Due after one year through five years	30.90%
Due after five years through ten years	22.50%
Due after ten years	1.40%
Asset and mortgage backed securities	35.70%
Total	100.00%
Fair Value
Due in one year or less	$ 81,888
Due after one year through five years	269,289
Due after five years through ten years	196,540
Due after ten years	11,601
Asset and mortgage backed securities	314,468
Total	$ 873,786	$ 884,861
Percent of Total
Due in one year or less	9.40%
Due after one year through five years	30.80%
Due after five years through ten years	22.50%
Due after ten years	1.30%
Asset and mortgage backed securities	36.00%
Total	100.00%