Segment and Other Operating Information - Earnings (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Condensed Consolidated Income Statements
Premiums and contract revenues	$ 58,352	$ 55,462	$ 115,285	$ 114,400
Net investment income (loss)	122,514	55,474	212,423	125,198
Other revenues	5,285	5,578	10,990	11,375
Total revenues	186,177	118,280	338,791	256,533
Life and other policy benefits	32,688	26,201	56,878	59,713
Market risk benefits expense	(788)	(55,492)	36,172	(116,498)
Amortization of deferred transaction costs	22,000	22,500	43,274	45,936
Universal life and annuity contract interest	32,947	(26,198)	63,159	(39,769)
Other operating expenses	62,443	30,322	87,126	62,903
Federal income taxes	7,253	24,420	10,244	50,159
Net earnings	29,634	96,527	41,938	194,089
Total segment assets
Condensed Consolidated Income Statements
Premiums and contract revenues	58,352	55,462	115,285	114,400
Net investment income (loss)	122,514	55,474	212,423	125,198
Other revenues	5,285	5,578	10,990	11,375
Total revenues	186,151	116,514	338,698	250,973
Life and other policy benefits	32,688	26,201	56,878	59,713
Policy benefit remeasurement (gain)/loss		0
Market risk benefits expense	(788)	(55,492)	36,172	(116,498)
Amortization of deferred transaction costs	22,000	22,500	43,274	45,936
Universal life and annuity contract interest	32,947	(26,198)	63,159	(39,769)
Other operating expenses	62,443	30,322	87,126	62,903
Federal income taxes	7,248	24,049	10,224	48,991
Total expenses	156,538	21,382	296,833	61,276
Net earnings	29,613	95,132	41,865	189,697
Total segment assets | Domestic Life Insurance
Condensed Consolidated Income Statements
Premiums and contract revenues	11,946	12,902	25,422	25,812
Net investment income (loss)	29,825	(5,955)	47,804	(8,942)
Other revenues	14	26	14	51
Total revenues	41,785	6,973	73,240	16,921
Life and other policy benefits	4,880	3,109	7,389	7,778
Policy benefit remeasurement (gain)/loss		0
Market risk benefits expense	0	0	0	0
Amortization of deferred transaction costs	3,209	3,048	6,375	6,541
Universal life and annuity contract interest	26,209	(9,804)	39,347	(16,577)
Other operating expenses	14,001	6,327	18,422	12,880
Federal income taxes	(1,198)	875	330	1,294
Total expenses	47,101	3,555	71,863	11,916
Net earnings	(5,316)	3,418	1,377	5,005
Total segment assets | International Life Insurance
Condensed Consolidated Income Statements
Premiums and contract revenues	21,540	19,073	41,605	38,309
Net investment income (loss)	8,669	(2,983)	14,067	(7,037)
Other revenues	2	17	4	39
Total revenues	30,211	16,107	55,676	31,311
Life and other policy benefits	3,652	2,725	5,530	6,629
Policy benefit remeasurement (gain)/loss		0
Market risk benefits expense	0	0	0	0
Amortization of deferred transaction costs	3,993	4,347	8,077	8,839
Universal life and annuity contract interest	7,134	(4,622)	10,946	(10,343)
Other operating expenses	11,182	4,377	14,908	9,737
Federal income taxes	912	1,880	3,135	3,379
Total expenses	26,873	8,707	42,596	18,241
Net earnings	3,338	7,400	13,080	13,070
Total segment assets | Annuities
Condensed Consolidated Income Statements
Premiums and contract revenues	6,362	4,656	10,602	11,962
Net investment income (loss)	61,189	55,549	114,270	116,210
Other revenues	1,786	1,369	3,802	2,598
Total revenues	69,337	61,574	128,674	130,770
Life and other policy benefits	9,736	7,335	14,736	17,625
Policy benefit remeasurement (gain)/loss		0
Market risk benefits expense	(788)	(55,492)	36,172	(116,498)
Amortization of deferred transaction costs	12,399	11,740	24,006	23,719
Universal life and annuity contract interest	(396)	(11,772)	12,866	(12,849)
Other operating expenses	30,067	12,809	40,651	26,978
Federal income taxes	3,407	19,566	47	39,395
Total expenses	54,425	(15,814)	128,478	(21,630)
Net earnings	14,912	77,388	196	152,400
Total segment assets | ONL & Affiliates
Condensed Consolidated Income Statements
Premiums and contract revenues	18,504	18,831	37,656	38,317
Net investment income (loss)	8,243	7,209	16,161	14,137
Other revenues	2,636	2,873	5,325	6,088
Total revenues	29,383	28,913	59,142	58,542
Life and other policy benefits	14,420	13,032	29,223	27,681
Policy benefit remeasurement (gain)/loss		0
Market risk benefits expense	0	0	0	0
Amortization of deferred transaction costs	2,399	3,365	4,816	6,837
Universal life and annuity contract interest	0	0	0	0
Other operating expenses	5,715	5,090	10,218	10,071
Federal income taxes	1,390	1,509	3,030	2,830
Total expenses	23,924	22,996	47,287	47,419
Net earnings	5,459	5,917	11,855	11,123
Total segment assets | All Others
Condensed Consolidated Income Statements
Premiums and contract revenues	0	0	0	0
Net investment income (loss)	14,588	1,654	20,121	10,830
Other revenues	847	1,293	1,845	2,599
Total revenues	15,435	2,947	21,966	13,429
Life and other policy benefits	0	0	0	0
Policy benefit remeasurement (gain)/loss		0
Market risk benefits expense	0	0	0	0
Amortization of deferred transaction costs	0	0	0	0
Universal life and annuity contract interest	0	0	0	0
Other operating expenses	1,478	1,719	2,927	3,237
Federal income taxes	2,737	219	3,682	2,093
Total expenses	4,215	1,938	6,609	5,330
Net earnings	$ 11,220	$ 1,009	$ 15,357	$ 8,099