Investments - Contractual Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Amortized Cost
Less: loaned securities	$ 139,121	$ 203,693
Total fixed-maturities, available for sale, Amortized Cost	5,511,501	5,599,111
Fair Value
Less: loaned securities	139,121	203,693
Total fixed-maturities available for sale, Fair Value	5,074,920	5,188,228
Non asset-backed securities
Amortized Cost
Due in one year or less	134,289
Due after one year through five years	1,104,983
Due after five years through 10 years	1,032,245
Due after 10 years	934,811
Fair Value
Due in one year or less	133,121
Due after one year through five years	1,067,941
Due after five years through 10 years	954,004
Due after 10 years	728,588
Asset-backed and mortgage-backed securities
Amortized Cost
Asset-backed and mortgage-backed securities	2,442,255
Fair Value
Asset-backed and mortgage-backed securities	2,321,118
Total fixed-maturities available for sale
Amortized Cost
Total	5,648,583	5,734,767
Total fixed-maturities, available for sale, Amortized Cost	5,511,501	5,599,111
Fair Value
Total	5,204,772	5,315,410
Total fixed-maturities available for sale, Fair Value	5,074,920	5,188,228
Fixed-maturities available for sale \| Total fixed-maturities available for sale
Amortized Cost
Total	5,648,583
Fair Value
Total	5,204,772
Loaned securities, amortized cost \| Total fixed-maturities available for sale
Amortized Cost
Less: loaned securities	137,082	135,656
Fair Value
Less: loaned securities	137,082	135,656
Loaned securities, fair value
Amortized Cost
Less: loaned securities	130,000
Fair Value
Less: loaned securities	130,000
Loaned securities, fair value \| Total fixed-maturities available for sale
Amortized Cost
Less: loaned securities	129,852	127,182
Fair Value
Less: loaned securities	$ 129,852	$ 127,182

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