Investments - Schedule of Contract Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Cost or Amortized Cost
One year or less	$ 108,264
After one year through five years	472,749
After five years through ten years	253,007
After ten years	131,425
Residential mortgage-backed	298,904
Commercial mortgage and asset-backed	274,448
Redeemable preferred stock	2,025
Total fixed maturity securities, Cost or Amortized Cost	1,540,822	$ 1,398,533
Fair Value
One year or less	108,823
After one year through five years	484,651
After five years through ten years	260,236
After ten years	138,709
Residential mortgage-backed	307,439
Commercial mortgage and asset-backed	268,979
Redeemable preferred stock	1,768
Total investments available-for-sale, Fair Value	$ 1,570,605	$ 1,433,626