Analysis of Shares Available for Grant (Detail)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant, beginning balance	6,099,342		255,263		1,724,540
Cancellation of available shares from prior plans	0		(229,333)		0
Expired and forfeited during year	5,850		0		26,269
Shares available for grant, ending balance	4,536,301		6,099,342		255,263
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation grants	(1,072,725)		(1,338,013)		(1,358,175)
Torchmark Corporation 2011 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Approval of shares under incentive plan	0	[1]	7,950,000	[1]	0	[1]
Torchmark Corporation 2011 Incentive Plan | Restricted Stock, Restricted Stock Units And Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation grants	(496,166)	[1]	(519,558)	[1]	0	[1]
Previous Plan | Restricted Stock and Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation grants	0		(19,017)		(137,371)

[1] Plan allows for grant of restricted stock such that each stock grant reduces 3.1 options available for grant