Liability For Future Policy Benefits (Future Policy Benefits) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Insurance [Abstract]
Benefit reserves, end of period, post-flooring	$ 7,569,229		$ 7,428,204
Deferred profit liability, end of period, post-flooring	15,038		18,731
Additional insurance reserves, including amounts in AOCI, end of period, post-flooring	14,596,254		13,252,702
Subtotal of amounts disclosed above	22,180,521		20,699,637
Other Future Policy Benefits reserves	1,181,797		1,059,906
Total Future policy Benefits	$ 23,362,318	$ 23,205,205	$ 21,759,543