Business Segments - Schedule of Segment Premium Revenue by Each Marketing Groups (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Amount	$ 2,998,720	$ 2,836,140	$ 2,749,682
% of Total	100.00%	100.00%	100.00%
United American Independent [Member]
Segment Reporting Information [Line Items]
Amount	$ 360,501	$ 322,350	$ 318,572
% of Total	12.00%	11.00%	11.00%
Liberty National Exclusive [Member]
Segment Reporting Information [Line Items]
Amount	$ 480,263	$ 494,282	$ 517,244
% of Total	16.00%	18.00%	19.00%
American Income Exclusive [Member]
Segment Reporting Information [Line Items]
Amount	$ 911,242	$ 845,180	$ 794,801
% of Total	30.00%	30.00%	29.00%
Family Heritage [Member]
Segment Reporting Information [Line Items]
Amount	$ 223,425	$ 206,262	$ 191,929
% of Total	8.00%	7.00%	7.00%
Globe Life Direct Response [Member]
Segment Reporting Information [Line Items]
Amount	$ 816,303	$ 760,689	$ 717,442
% of Total	27.00%	27.00%	26.00%
Other [Member]
Segment Reporting Information [Line Items]
Amount	$ 206,986	$ 207,377	$ 209,694
% of Total	7.00%	7.00%	8.00%
Life Insurance [Member]
Segment Reporting Information [Line Items]
Amount	$ 2,073,065	$ 1,966,300	$ 1,885,332
% of Total	100.00%	100.00%	100.00%
Life Insurance [Member] | United American Independent [Member]
Segment Reporting Information [Line Items]
Amount	$ 15,036	$ 16,582	$ 19,742
% of Total	1.00%	1.00%	1.00%
Life Insurance [Member] | Liberty National Exclusive [Member]
Segment Reporting Information [Line Items]
Amount	$ 271,113	$ 272,265	$ 275,980
% of Total	13.00%	14.00%	15.00%
Life Insurance [Member] | American Income Exclusive [Member]
Segment Reporting Information [Line Items]
Amount	$ 830,903	$ 766,458	$ 715,366
% of Total	40.00%	39.00%	38.00%
Life Insurance [Member] | Family Heritage [Member]
Segment Reporting Information [Line Items]
Amount	$ 2,334	$ 1,595	$ 1,006
% of Total	0.00%	0.00%	0.00%
Life Insurance [Member] | Globe Life Direct Response [Member]
Segment Reporting Information [Line Items]
Amount	$ 746,693	$ 702,023	$ 663,544
% of Total	36.00%	36.00%	35.00%
Life Insurance [Member] | Other [Member]
Segment Reporting Information [Line Items]
Amount	$ 206,986	$ 207,377	$ 209,694
% of Total	10.00%	10.00%	11.00%
Health Insurance [Member]
Segment Reporting Information [Line Items]
Amount	$ 925,520	$ 869,440	$ 863,818
% of Total	100.00%	100.00%	100.00%
Health Insurance [Member] | United American Independent [Member]
Segment Reporting Information [Line Items]
Amount	$ 345,330	$ 305,368	$ 298,298
% of Total	37.00%	35.00%	35.00%
Health Insurance [Member] | Liberty National Exclusive [Member]
Segment Reporting Information [Line Items]
Amount	$ 209,150	$ 222,017	$ 241,264
% of Total	23.00%	25.00%	28.00%
Health Insurance [Member] | American Income Exclusive [Member]
Segment Reporting Information [Line Items]
Amount	$ 80,339	$ 78,722	$ 79,435
% of Total	9.00%	9.00%	9.00%
Health Insurance [Member] | Family Heritage [Member]
Segment Reporting Information [Line Items]
Amount	$ 221,091	$ 204,667	$ 190,923
% of Total	24.00%	24.00%	22.00%
Health Insurance [Member] | Globe Life Direct Response [Member]
Segment Reporting Information [Line Items]
Amount	$ 69,610	$ 58,666	$ 53,898
% of Total	7.00%	7.00%	6.00%
Health Insurance [Member] | Other [Member]
Segment Reporting Information [Line Items]
% of Total
Annuity [Member]
Segment Reporting Information [Line Items]
Amount	$ 135	$ 400	$ 532
% of Total	100.00%	100.00%	100.00%
Annuity [Member] | United American Independent [Member]
Segment Reporting Information [Line Items]
Amount	$ 135	$ 400	$ 532
% of Total	100.00%	100.00%	100.00%