Analysis of Shares Available for Grant (Parenthetical) (Detail)	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ratio by which each grant of restricted stock reduces shares available for options	3.1

The ratio by which each grant of restricted stock reduces shares available for option

No definition available.

Name:	tmk_RatioByWhichEachGrantOfRestrictedStockReducesSharesAvailableForOptions
Namespace Prefix:	tmk_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant