Policy Liabilities - Summary Of Policyholder Account Balance (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Interest Sensitive Life
Policyholder Account Balance [Roll Forward]
Beginning Balance	$ 739,105,000	$ 745,335,000
Issuances	0	0
Premiums received	6,030,000	6,297,000
Policy charges	(3,319,000)	(3,474,000)
Surrenders and withdrawals	(5,384,000)	(5,280,000)
Benefit payments	(7,844,000)	(8,999,000)
Interest credited	7,135,000	7,170,000
Other	2,177,000	3,195,000
Ending Balance	$ 737,900,000	$ 744,244,000
Weighted-average credit rate	3.92%	3.91%
Net amount at risk	$ 1,847,128,000	$ 1,952,631,000
Cash surrender value	676,247,000	693,201,000
Deferred Annuity
Policyholder Account Balance [Roll Forward]
Beginning Balance	954,318,000	1,033,525,000
Issuances	202,000	340,000
Premiums received	4,776,000	8,216,000
Policy charges	0	0
Surrenders and withdrawals	(43,533,000)	(11,873,000)
Benefit payments	(15,784,000)	(12,073,000)
Interest credited	7,560,000	8,290,000
Other	258,000	662,000
Ending Balance	$ 907,797,000	$ 1,027,087,000
Weighted-average credit rate	3.29%	3.26%
Cash surrender value	$ 907,797,000	$ 1,027,064,000
Other Policyholders' Funds
Policyholder Account Balance [Roll Forward]
Beginning Balance	123,234,000	99,468,000
Issuances	0	0
Premiums received	21,662,000	2,044,000
Policy charges	0	0
Surrenders and withdrawals	(3,303,000)	(2,805,000)
Benefit payments	0	0
Interest credited	1,238,000	1,125,000
Other	(145,000)	292,000
Ending Balance	$ 142,686,000	$ 100,124,000
Weighted-average credit rate	3.78%	4.58%
Cash surrender value	$ 142,686,000	$ 100,124,000