Investments - Schedule of Contractual Maturities of Fixed Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Amortized Cost
Amortized Cost	$ 3,489,236	$ 3,410,992
Fair Value
Fair Value	3,470,507	3,439,002
Total fixed maturities
Amortized Cost
Amortized Cost	3,133,507	3,210,940
Fair Value
Fair Value	3,114,054	$ 3,238,543
Fixed Maturities, Excluding Mortgage-backed and Asset-backed Securities
Amortized Cost
Due less than one year	54,757
Due after one through five years	1,583,956
Due after five through ten years	790,011
Due after ten years	72,282
Fair Value
Due less than one year	54,964
Due after one through five years	1,578,545
Due after five through ten years	782,759
Due after ten years	71,370
Mortgage-backed securities
Amortized Cost
Mortgage/Asset-backed	358,307
Fair Value
Mortgage/Asset-backed	352,726
Asset-backed securities
Amortized Cost
Mortgage/Asset-backed	274,194
Fair Value
Mortgage/Asset-backed	$ 273,690

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