Policy Liabilities - Schedule of Policyholder Account Balance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest Sensitive Life
Policyholder Account Balance [Roll Forward]
Beginning Balance	$ 739,105	$ 745,335	$ 750,892
Issuances	0	0	0
Premiums received	22,036	23,439	25,038
Policy charges	(12,926)	(13,573)	(14,261)
Surrenders and withdrawals	(21,215)	(21,994)	(21,029)
Benefit payments	(29,909)	(32,889)	(36,661)
Interest credited	28,320	28,579	28,941
Other	7,537	10,208	12,415
Ending Balance	$ 732,948	$ 739,105	$ 745,335
Weighted-average credit rate	3.85%	3.85%	3.87%
Net amount at risk	$ 1,766,170	$ 1,873,315	$ 1,980,518
Cash surrender value	671,596	689,546	693,845
Deferred Annuity
Policyholder Account Balance [Roll Forward]
Beginning Balance	954,318	1,033,525	1,062,999
Issuances	896	1,528	1,738
Premiums received	13,209	22,873	28,126
Policy charges	0	0	0
Surrenders and withdrawals	(165,584)	(92,235)	(48,641)
Benefit payments	(57,937)	(44,456)	(45,967)
Interest credited	28,150	32,779	33,866
Other	(13)	304	1,404
Ending Balance	$ 773,039	$ 954,318	$ 1,033,525
Weighted-average credit rate	3.26%	3.30%	3.23%
Cash surrender value	$ 773,039	$ 954,309	$ 1,033,491
Other Policy-holders' Funds
Policyholder Account Balance [Roll Forward]
Beginning Balance	123,236	99,468	98,460
Issuances	0	0	0
Premiums received	122,136	30,591	7,784
Policy charges	0	0	0
Surrenders and withdrawals	(13,042)	(11,615)	(11,452)
Benefit payments	0	0	0
Interest credited	9,314	4,589	4,503
Other	(4,686)	203	173
Ending Balance	$ 236,958	$ 123,236	$ 99,468
Weighted-average credit rate	5.17%	4.12%	4.55%
Cash surrender value	$ 236,958	$ 123,234	$ 99,470