Segment and Other Operating Information - Operating Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Selected Balance Sheet Items:
Total segment assets	$ 14,330,189	$ 14,648,270	$ 12,553,447
Future policy benefits			15,000
Other policyholder liabilities	134,338	138,480
Funds withheld liability	1,485,267	1,697,591
Condensed Income Statements:
Premiums and contract revenues	224,297	237,947	239,969
Net investment income	562,530	417,202	555,492
Other revenues	22,314	18,522	17,486
Realized gains on investments	14,950	21,071	6,241
Total revenues	824,091	694,742	819,188
Life and other policy benefits	187,577	131,337	137,342
Amortization of deferred transaction costs	69,461	140,503	116,802
Universal life and annuity contract interest	213,184	206,250	295,330
Other operating expenses	126,612	104,584	104,558
Federal income taxes (benefit)	46,576	19,756	33,540
Net earnings (loss)	180,681	92,312	131,616
Restatement Adjustment
Selected Balance Sheet Items:
Future policy benefits			15,000
Segments
Selected Balance Sheet Items:
Deferred transaction costs	892,160	691,733	966,402
Total segment assets	13,426,665	13,753,320	12,092,796
Future policy benefits	9,912,987	9,933,419	10,141,971
Other policyholder liabilities	134,338	138,480	127,607
Funds withheld liability	1,485,267	1,697,591
Condensed Income Statements:
Premiums and contract revenues	224,297	237,947	239,969
Net investment income	562,530	417,202	555,492
Other revenues	22,314	18,522	17,486
Total revenues	809,141	673,671	812,947
Life and other policy benefits	187,577	131,337	137,342
Amortization of deferred transaction costs	69,461	140,503	116,802
Universal life and annuity contract interest	213,184	206,250	295,330
Other operating expenses	126,612	104,584	104,558
Federal income taxes (benefit)	43,436	15,331	32,229
Total expenses	640,270	598,005	686,261
Net earnings (loss)	168,871	75,666	126,686
Segments | Domestic Life Insurance
Selected Balance Sheet Items:
Deferred transaction costs	150,688	94,100	127,557
Total segment assets	1,791,017	3,242,794	1,399,818
Future policy benefits	1,537,482	1,337,174	1,198,103
Other policyholder liabilities	20,950	16,378	18,016
Funds withheld liability	0	0
Condensed Income Statements:
Premiums and contract revenues	51,294	53,834	45,709
Net investment income	90,006	54,516	77,672
Other revenues	105	58	313
Total revenues	141,405	108,408	123,694
Life and other policy benefits	24,416	18,471	18,948
Amortization of deferred transaction costs	9,580	17,661	11,797
Universal life and annuity contract interest	77,246	44,782	69,849
Other operating expenses	26,959	25,730	20,376
Federal income taxes (benefit)	656	265	561
Total expenses	138,857	106,909	121,531
Net earnings (loss)	2,548	1,499	2,163
Segments | International Life Insurance
Selected Balance Sheet Items:
Deferred transaction costs	152,340	124,480	209,858
Total segment assets	975,942	1,034,280	1,153,105
Future policy benefits	749,537	798,952	870,461
Other policyholder liabilities	14,268	11,086	14,903
Funds withheld liability	0	0
Condensed Income Statements:
Premiums and contract revenues	79,085	88,167	99,417
Net investment income	52,227	27,273	47,004
Other revenues	95	67	86
Total revenues	131,407	115,507	146,507
Life and other policy benefits	26,481	14,084	17,064
Amortization of deferred transaction costs	(11,118)	24,929	17,593
Universal life and annuity contract interest	31,696	(2,087)	48,561
Other operating expenses	19,679	17,829	19,447
Federal income taxes (benefit)	13,249	9,143	9,024
Total expenses	79,987	63,898	111,689
Net earnings (loss)	51,420	51,609	34,818
Segments | Annuities
Selected Balance Sheet Items:
Deferred transaction costs	423,318	302,397	486,553
Total segment assets	9,187,610	7,976,588	8,198,730
Future policy benefits	6,843,457	7,028,860	7,366,894
Other policyholder liabilities	82,650	94,049	80,002
Funds withheld liability	1,485,267	1,697,591
Condensed Income Statements:
Premiums and contract revenues	16,809	17,025	20,317
Net investment income	368,234	290,576	380,357
Other revenues	5,374	43	(34)
Total revenues	390,417	307,644	400,640
Life and other policy benefits	67,515	31,043	41,487
Amortization of deferred transaction costs	61,881	87,133	79,064
Universal life and annuity contract interest	104,242	163,555	176,920
Other operating expenses	53,817	36,870	35,699
Federal income taxes (benefit)	21,094	(1,649)	13,888
Total expenses	308,549	316,952	347,058
Net earnings (loss)	81,868	(9,308)	53,582
Segments | ONL & Affiliates
Selected Balance Sheet Items:
Deferred transaction costs	165,814	170,756	142,434
Total segment assets	1,115,380	1,117,509	978,243
Future policy benefits	782,511	768,433	706,513
Other policyholder liabilities	16,470	16,967	14,686
Funds withheld liability	0	0
Condensed Income Statements:
Premiums and contract revenues	77,109	78,921	74,526
Net investment income	26,989	26,383	22,593
Other revenues	12,654	10,118	8,445
Total revenues	116,752	115,422	105,564
Life and other policy benefits	69,165	67,739	59,843
Amortization of deferred transaction costs	9,118	10,780	8,348
Universal life and annuity contract interest	0	0	0
Other operating expenses	20,244	18,454	17,056
Federal income taxes (benefit)	3,675	4,413	3,700
Total expenses	102,202	101,386	88,947
Net earnings (loss)	14,550	14,036	16,617
Segments | All Others
Selected Balance Sheet Items:
Deferred transaction costs	0	0	0
Total segment assets	356,716	382,149	362,900
Future policy benefits	0	0	0
Other policyholder liabilities	0	0	0
Funds withheld liability	0	0
Condensed Income Statements:
Premiums and contract revenues	0	0	0
Net investment income	25,074	18,454	27,866
Other revenues	4,086	8,236	8,676
Total revenues	29,160	26,690	36,542
Life and other policy benefits	0	0	0
Amortization of deferred transaction costs	0	0	0
Universal life and annuity contract interest	0	0	0
Other operating expenses	5,913	5,701	11,980
Federal income taxes (benefit)	4,762	3,159	5,056
Total expenses	10,675	8,860	17,036
Net earnings (loss)	18,485	17,830	19,506
Segment Reconciling Items
Condensed Income Statements:
Taxes on realized gains on investments	3,140	4,425	1,311
Realized gains on investments, net of taxes	11,810	16,646	4,930
Other unallocated
Selected Balance Sheet Items:
Total segment assets	$ 903,524	$ 894,950	$ 460,651