Investments - Schedule of Contract Maturities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Cost or Amortized Cost
One year or less	$ 94,222
After one year through five years	519,366
After five years through ten years	364,892
After ten years	260,423
Residential mortgage-backed	467,134
Commercial mortgage and asset-backed	340,212
Total fixed maturity securities, Cost or Amortized Cost	2,046,249
Fair Value
One year or less	92,437
After one year through five years	492,322
After five years through ten years	323,047
After ten years	222,135
Residential mortgage-backed	430,248
Commercial mortgage and asset-backed	315,506
Total investments available-for-sale, Fair Value	$ 1,875,695	$ 1,783,417