Investments (Accrued Investment Income) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Net Investment Income
Accrued investment income	$ 283,585	$ 219,635
Fixed maturities
Net Investment Income
Accrued investment income	240,885	187,628
Equity securities
Net Investment Income
Accrued investment income	220	349
Commercial mortgage and other loans
Net Investment Income
Accrued investment income	16,962	13,335
Policy loans
Net Investment Income
Accrued investment income	20,247	14,525
Other invested assets
Net Investment Income
Accrued investment income	47	48
Short-term investments and cash equivalents
Net Investment Income
Accrued investment income	$ 5,224	$ 3,750