Business Segments - Segment Premium Income by Distribution Channel and Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($)
Segment Reporting [Abstract]
Number of segments | segment			4
Segment Reporting Information [Line Items]
Revenue	$ 1,074,405	$ 1,028,067	$ 3,225,120	$ 3,054,116
% of Total	100.00%	100.00%	100.00%	100.00%
Life
Segment Reporting Information [Line Items]
Revenue	$ 755,115	$ 728,924	$ 2,269,641	$ 2,165,213
% of Total	100.00%	100.00%	100.00%	100.00%
Health
Segment Reporting Information [Line Items]
Revenue	$ 319,289	$ 299,143	$ 955,478	$ 888,902
% of Total	100.00%	100.00%	100.00%	100.00%
Annuity
Segment Reporting Information [Line Items]
Revenue	$ 1	$ 0	$ 1	$ 1
% of Total	100.00%	0.00%	100.00%	100.00%
American Income
Segment Reporting Information [Line Items]
Revenue	$ 408,000	$ 385,526	$ 1,212,652	$ 1,124,257
% of Total	38.00%	37.00%	38.00%	37.00%
American Income | Life
Segment Reporting Information [Line Items]
Revenue	$ 378,306	$ 356,456	$ 1,124,712	$ 1,039,047
% of Total	50.00%	49.00%	50.00%	48.00%
American Income | Health
Segment Reporting Information [Line Items]
Revenue	$ 29,694	$ 29,070	$ 87,940	$ 85,210
% of Total	9.00%	10.00%	9.00%	10.00%
American Income | Annuity
Segment Reporting Information [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0
% of Total	0.00%	0.00%	0.00%	0.00%
Direct to Consumer
Segment Reporting Information [Line Items]
Revenue	$ 260,005	$ 258,770	$ 796,843	$ 790,048
% of Total	24.00%	25.00%	25.00%	26.00%
Direct to Consumer | Life
Segment Reporting Information [Line Items]
Revenue	$ 242,550	$ 240,578	$ 743,041	$ 734,046
% of Total	32.00%	33.00%	33.00%	34.00%
Direct to Consumer | Health
Segment Reporting Information [Line Items]
Revenue	$ 17,455	$ 18,192	$ 53,802	$ 56,002
% of Total	6.00%	6.00%	6.00%	6.00%
Direct to Consumer | Annuity
Segment Reporting Information [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0
% of Total	0.00%	0.00%	0.00%	0.00%
Liberty National
Segment Reporting Information [Line Items]
Revenue	$ 127,881	$ 125,244	$ 383,892	$ 372,992
% of Total	12.00%	12.00%	12.00%	12.00%
Liberty National | Life
Segment Reporting Information [Line Items]
Revenue	$ 82,072	$ 78,528	$ 244,242	$ 232,118
% of Total	11.00%	11.00%	11.00%	11.00%
Liberty National | Health
Segment Reporting Information [Line Items]
Revenue	$ 45,809	$ 46,716	$ 139,650	$ 140,874
% of Total	14.00%	16.00%	15.00%	16.00%
Liberty National | Annuity
Segment Reporting Information [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0
% of Total	0.00%	0.00%	0.00%	0.00%
United American
Segment Reporting Information [Line Items]
Revenue	$ 136,150	$ 120,439	$ 407,680	$ 358,282
% of Total	13.00%	12.00%	13.00%	12.00%
United American | Life
Segment Reporting Information [Line Items]
Revenue	$ 1,949	$ 2,199	$ 6,022	$ 6,737
% of Total	0.00%	0.00%	0.00%	0.00%
United American | Health
Segment Reporting Information [Line Items]
Revenue	$ 134,200	$ 118,240	$ 401,657	$ 351,544
% of Total	42.00%	39.00%	42.00%	39.00%
United American | Annuity
Segment Reporting Information [Line Items]
Revenue	$ 1	$ 0	$ 1	$ 1
% of Total	100.00%	0.00%	100.00%	100.00%
Family Heritage
Segment Reporting Information [Line Items]
Revenue	$ 93,539	$ 88,211	$ 276,576	$ 258,902
% of Total	9.00%	9.00%	8.00%	8.00%
Family Heritage | Life
Segment Reporting Information [Line Items]
Revenue	$ 1,408	$ 1,286	$ 4,147	$ 3,630
% of Total	0.00%	0.00%	0.00%	0.00%
Family Heritage | Health
Segment Reporting Information [Line Items]
Revenue	$ 92,131	$ 86,925	$ 272,429	$ 255,272
% of Total	29.00%	29.00%	28.00%	29.00%
Family Heritage | Annuity
Segment Reporting Information [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0
% of Total	0.00%	0.00%	0.00%	0.00%
Other
Segment Reporting Information [Line Items]
Revenue	$ 48,830	$ 49,877	$ 147,477	$ 149,635
% of Total	4.00%	5.00%	4.00%	5.00%
Other | Life
Segment Reporting Information [Line Items]
Revenue	$ 48,830	$ 49,877	$ 147,477	$ 149,635
% of Total	7.00%	7.00%	6.00%	7.00%
Other | Health
Segment Reporting Information [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0
% of Total	0.00%	0.00%	0.00%	0.00%
Other | Annuity
Segment Reporting Information [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0
% of Total	0.00%	0.00%	0.00%	0.00%