Investments (Accrued Investment Income) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Net Investment Income
Accrued investment income	$ 426,302	$ 333,838
Fixed maturities
Net Investment Income
Accrued investment income	343,332	272,031
Equity securities
Net Investment Income
Accrued investment income	220	220
Commercial mortgage and other loans
Net Investment Income
Accrued investment income	23,906	21,070
Policy loans
Net Investment Income
Accrued investment income	52,057	35,210
Other invested assets
Net Investment Income
Accrued investment income	0	43
Short-term investments and cash equivalents
Net Investment Income
Accrued investment income	$ 6,787	$ 5,264