Investments - Schedule of Contract Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Cost or Amortized Cost
One year or less	$ 45,678
After one year through five years	344,201
After five years through ten years	260,473
After ten years	169,776
Residential mortgage-backed	330,117
Commercial mortgage and asset-backed	227,720
Total fixed maturity securities, Cost or Amortized Cost	1,377,965
Fair Value
One year or less	45,113
After one year through five years	334,549
After five years through ten years	236,295
After ten years	148,002
Residential mortgage-backed	307,526
Commercial mortgage and asset-backed	215,981
Total investments available-for-sale, Fair Value	$ 1,287,466	$ 1,324,476