Investments (Securities Pledged) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total securities pledged	$ 3,956,834	$ 4,254,386
Total liabilities supported by pledged collateral	3,743,968	2,869,657
Equity securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total securities pledged	100,601	172,995
Cash collateral for loaned securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total liabilities supported by pledged collateral	121,372	218,310
Available-for-sale | Fixed maturities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total securities pledged	3,856,216	4,081,391
Trading | Fixed maturities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Total securities pledged	$ 17	$ 0