Policy Liabilities - Schedule of Policyholder Account Balance (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Interest Sensitive Life
Policyholder Account Balance [Roll Forward]
Beginning Balance	$ 737,900,000	$ 744,244,000	$ 739,105,000	$ 745,335,000
Issuances	0	0	0	0
Premiums received	5,634,000	6,090,000	11,664,000	12,387,000
Policy charges	(3,197,000)	(3,400,000)	(6,516,000)	(6,874,000)
Surrenders and withdrawals	(5,238,000)	(5,473,000)	(10,622,000)	(10,753,000)
Benefit payments	(7,651,000)	(9,362,000)	(15,495,000)	(18,361,000)
Interest credited	7,056,000	7,195,000	14,191,000	14,365,000
Other	2,416,000	2,999,000	4,593,000	6,194,000
Ending Balance	$ 736,920,000	$ 742,293,000	$ 736,920,000	$ 742,293,000
Weighted-average credit rate	3.88%	3.93%	3.88%	3.93%
Net amount at risk	$ 1,819,695,000	$ 1,924,662,000	$ 1,819,695,000	$ 1,924,662,000
Cash surrender value	675,044,000	691,193,000	675,044,000	691,193,000
Deferred Annuity
Policyholder Account Balance [Roll Forward]
Beginning Balance	907,797,000	1,027,087,000	954,318,000	1,033,525,000
Issuances	169,000	353,000	371,000	693,000
Premiums received	3,328,000	5,858,000	8,104,000	14,074,000
Policy charges	0	0	0	0
Surrenders and withdrawals	(43,738,000)	(14,243,000)	(87,271,000)	(26,116,000)
Benefit payments	(21,628,000)	(11,379,000)	(37,412,000)	(23,452,000)
Interest credited	7,185,000	8,300,000	14,745,000	16,590,000
Other	(49,000)	(172,000)	209,000	490,000
Ending Balance	$ 853,064,000	$ 1,015,804,000	$ 853,064,000	$ 1,015,804,000
Weighted-average credit rate	3.30%	3.29%	3.30%	3.29%
Cash surrender value	$ 853,064,000	$ 1,015,786,000	$ 853,064,000	$ 1,015,786,000
Other Policyholders' Funds
Policyholder Account Balance [Roll Forward]
Beginning Balance	142,686,000	100,124,000	123,234,000	99,468,000
Issuances	0	0	0	0
Premiums received	46,747,000	1,848,000	68,409,000	3,892,000
Policy charges	0	0	0	0
Surrenders and withdrawals	(3,021,000)	(2,837,000)	(6,324,000)	(5,642,000)
Benefit payments	0	0	0	0
Interest credited	2,101,000	1,133,000	3,339,000	2,258,000
Other	(640,000)	(34,000)	(785,000)	258,000
Ending Balance	$ 187,873,000	$ 100,234,000	$ 187,873,000	$ 100,234,000
Weighted-average credit rate	5.18%	4.60%	5.18%	4.60%
Cash surrender value	$ 187,872,000	$ 100,234,000	$ 187,872,000	$ 100,234,000