Investments (Accrued Investment Income) (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Net Investment Income
Accrued investment income	$ 502,312	$ 466,394
Fixed maturities
Net Investment Income
Accrued investment income	423,507	396,173
Equity securities
Net Investment Income
Accrued investment income	218	436
Commercial mortgage and other loans
Net Investment Income
Accrued investment income	31,636	29,437
Policy loans
Net Investment Income
Accrued investment income	41,601	30,820
Short-term investments and cash equivalents
Net Investment Income
Accrued investment income	$ 5,350	$ 9,528