Impacts of New Accounting Standards to Operating Income & Comprehensive Income Statements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in future policy benefit reserves									$ (5,624)	$ 4,804	$ 9,773
Policyholder liability remeasurement (gain) loss									4,460	2,884	1,434
Amortization of deferred policy acquisition costs									15,460	14,390	13,445
Amortization of cost of customer relationships acquired									604	621	757
Federal income tax expense (benefit)	$ (1,967)	$ 1,943	$ (82)	$ 1,843	$ (2,248)	$ 1,415	$ 1,474	$ 729	1,737	1,370	(42,201)
Net income (loss)	$ 10,741	$ 2,698	$ 6,126	$ 4,872	$ 13,659	$ 3,407	$ 2,492	$ 6,449	24,437	26,007	72,706
Unrealized gains (losses) on fixed maturity securities, net									51,650	(328,569)	(41,366)
Change in current discount rate for liability for future policy benefits									(34,790)	337,776	92,396
Income tax expense (benefit) on other comprehensive income items									(2,029)	7,262	1,449
Other comprehensive income (loss)									18,889	1,945	49,581
Total comprehensive income (loss)									$ 43,326	$ 27,952	$ 122,287
Common Stock Class A [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earnings Per Share, Basic	$ 0.21	$ 0.06	$ 0.12	$ 0.10	$ 0.27	$ 0.07	$ 0.05	$ 0.13	$ 0.49	$ 0.52	$ 1.46
Earnings Per Share, Diluted	$ 0.21	$ 0.05	$ 0.12	$ 0.10	$ 0.27	$ 0.06	$ 0.05	$ 0.13	0.48	0.51	1.44
Common Stock Class B [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earnings Per Share, Basic									0	0	0.73
Earnings Per Share, Diluted									$ 0	$ 0	$ 0.72
Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in future policy benefit reserves										$ 29,640	$ 36,444
Policyholder liability remeasurement (gain) loss										0	0
Amortization of deferred policy acquisition costs										26,529	24,952
Amortization of cost of customer relationships acquired										974	1,206
Federal income tax expense (benefit)										(429)	(43,475)
Net income (loss)										(6,638)	36,787
Unrealized gains (losses) on fixed maturity securities, net										(330,765)	(5,298)
Change in current discount rate for liability for future policy benefits										0	0
Income tax expense (benefit) on other comprehensive income items										17,994	(5,465)
Other comprehensive income (loss)										(312,771)	(10,763)
Total comprehensive income (loss)										$ (319,409)	$ 26,024
Previously Reported | Common Stock Class A [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earnings Per Share, Basic										$ (0.13)	$ 0.74
Earnings Per Share, Diluted										(0.13)	0.73
Previously Reported | Common Stock Class B [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earnings Per Share, Basic										0	0.37
Earnings Per Share, Diluted										$ 0	$ 0.36
Revision of Prior Period, Accounting Standards Update, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in future policy benefit reserves										$ (24,836)	$ (26,671)
Policyholder liability remeasurement (gain) loss										2,884	1,434
Amortization of deferred policy acquisition costs										(12,139)	(11,507)
Amortization of cost of customer relationships acquired										(353)	(449)
Federal income tax expense (benefit)										1,799	1,274
Net income (loss)										32,645	35,919
Unrealized gains (losses) on fixed maturity securities, net										2,196	(36,068)
Change in current discount rate for liability for future policy benefits										337,776	92,396
Income tax expense (benefit) on other comprehensive income items										(25,256)	4,016
Other comprehensive income (loss)										314,716	60,344
Total comprehensive income (loss)										$ 347,361	$ 96,263
Revision of Prior Period, Accounting Standards Update, Adjustment | Common Stock Class A [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earnings Per Share, Basic										$ 0.65	$ 0.72
Earnings Per Share, Diluted										0.64	0.71
Revision of Prior Period, Accounting Standards Update, Adjustment | Common Stock Class B [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earnings Per Share, Basic										0	0.36
Earnings Per Share, Diluted										$ 0	$ 0.36