Investments - Contractual Maturities (Details) - USD ($) $ in Thousands		Mar. 31, 2025		Dec. 31, 2024
Amortized Cost
Less: loaned securities		$ 154,891		$ 139,121
Fixed-maturities available for sale, amortized cost		5,479,486		5,511,501
Fair Value
Less: loaned securities		154,891		139,121
Total fixed-maturities available for sale, Fair Value		5,112,192		5,074,920
Non asset-backed securities
Amortized Cost
Due in one year or less		116,836
Due after one year through five years	[1]	1,068,443
Due after five years through 10 years	[1]	1,063,636
Due after 10 years	[1]	909,525
Fair Value
Due in one year or less		115,488
Due after one year through five years	[1]	1,040,580
Due after five years through 10 years	[1]	1,007,473
Due after 10 years	[1]	715,630
Asset-backed and mortgage-backed securities
Amortized Cost
Asset-backed and mortgage-backed securities	[2]	2,458,278
Fair Value
Asset-backed and mortgage-backed securities	[2]	2,363,959
Total fixed-maturities available for sale
Amortized Cost
Total		5,616,718		5,648,583
Fixed-maturities available for sale, amortized cost		5,479,486		5,511,501	[3]
Fair Value
Total		5,243,130		5,204,772
Total fixed-maturities available for sale, Fair Value		5,112,192		5,074,920	[3]
Fixed-maturities available for sale | Total fixed-maturities available for sale
Amortized Cost
Total		5,616,718
Fair Value
Total		5,243,130
Loaned securities, amortized cost | Total fixed-maturities available for sale
Amortized Cost
Less: loaned securities		137,232	[3]	137,082
Fair Value
Less: loaned securities		137,232	[3]	137,082
Loaned securities, fair value | Total fixed-maturities available for sale
Amortized Cost
Less: loaned securities		130,938	[3]	129,852
Fair Value
Less: loaned securities		$ 130,938	[3]	$ 129,852

[1] Actual maturities may differ as a result of calls before scheduled maturity.

[2] Includes RMBS, CMBS, CLO, Other ABS and mortgage insurance-linked notes, which are not due at a single maturity date.

[3] Included in other assets on our condensed consolidated balance sheets. See “Loaned Securities” below for a discussion of our securities lending agreements.