Summary of Business and Significant Accounting Policies - Revised Balance Sheet and Statements of Comprehensive Income (Loss) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue	$ 194,981	$ 157,526	$ 357,565	$ 352,508	$ 480,339
Income (loss) from operations	(172,906)	(54,561)	123,445	(227,466)	129,324
Income (loss) before income tax expense (benefit)	(183,544)	(63,198)	116,247	(246,741)	114,585
Income tax expense (benefit)	(46,536)	(16,045)	26,391	(62,580)	24,994
Net income (loss)	$ (137,008)	$ (47,153)	$ 89,856	$ (184,161)	$ 89,591
Basic (in dollars per share)	$ (0.84)	$ (0.29)	$ 0.55	$ (1.12)	$ 0.55
Diluted (in dollars per share)	$ (0.84)	$ (0.29)	$ 0.54	$ (1.12)	$ 0.54
COMPREHENSIVE INCOME	$ (135,233)	$ (47,159)	$ 89,972	$ (182,392)	$ 89,450
Accounts receivable	149,399			149,399		$ 105,298
Total current assets	555,556			555,556		485,358
Total assets	1,444,833			1,444,833		1,425,795
Deferred income taxes	76,942			76,942		139,240
Total liabilities	952,429			952,429		757,235
Retained earnings (accumulated deficit)	(62,236)			(62,236)		121,925
Total shareholders’ equity	492,404	625,668	630,970	492,404	630,970	668,560	$ 544,186	$ 542,369
Total liabilities and shareholders’ equity	1,444,833			1,444,833		1,425,795
Life
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue	32,780		35,666	80,211	77,094
Final expense | Life
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue	10,886		9,816	35,473	26,274
Commission
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue	140,701	132,254	320,265	272,956	425,415
Commission | Life
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue	$ 27,012		29,844	$ 67,845	66,046
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue		159,923	358,274		482,443
Income (loss) from operations		(52,164)	124,154		131,428
Income (loss) before income tax expense (benefit)		(60,801)	116,956		116,689
Income tax expense (benefit)		(15,436)	26,540		25,436
Net income (loss)		$ (45,365)	$ 90,416		$ 91,253
Basic (in dollars per share)		$ (0.28)	$ 0.56		$ 0.56
Diluted (in dollars per share)		$ (0.28)	$ 0.55		$ 0.55
COMPREHENSIVE INCOME		$ (45,371)	$ 90,532		$ 91,112
Accounts receivable						113,375
Total current assets						493,435
Total assets						1,433,872
Deferred income taxes						140,988
Total liabilities						758,983
Retained earnings (accumulated deficit)						128,254
Total shareholders’ equity			634,135		634,135	674,889	545,689	544,974
Total liabilities and shareholders’ equity						1,433,872
As Previously Reported | Commission
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue		134,651	320,974		427,519
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue		(2,397)	(709)		(2,104)
Income (loss) from operations		(2,397)	(709)		(2,104)
Income (loss) before income tax expense (benefit)		(2,397)	(709)		(2,104)
Income tax expense (benefit)		(609)	(149)		(442)
Net income (loss)		$ (1,788)	$ (560)		$ (1,662)	(4,800)
Basic (in dollars per share)		$ (0.01)	$ (0.01)		$ (0.01)
Diluted (in dollars per share)		$ (0.01)	$ (0.01)		$ (0.01)
COMPREHENSIVE INCOME		$ (1,788)	$ (560)		$ (1,662)
Accounts receivable						(8,077)	(2,000)
Total current assets						(8,077)
Total assets						(8,077)
Deferred income taxes						(1,748)
Total liabilities						(1,748)
Retained earnings (accumulated deficit)						(6,329)
Total shareholders’ equity			(3,165)		(3,165)	(6,329)	(1,503)	$ (2,605)
Total liabilities and shareholders’ equity						(8,077)
Adjustment | Commission
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue		$ (2,397)	$ (709)		$ (2,104)	$ (6,100)	$ (2,000)