Schedule of Additional Information about Investments in Unrealized Loss Position (Detail)	Sep. 30, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Number of issues (Cusip numbers) held, Less than Twelve Months	73	117
Number of issues (Cusip numbers) held, Twelve Months or Longer	72	93
Number of issues (Cusip numbers) held, Total	145	210

Available for sale securities in unrealized loss positions qualitative disclosure number of positions 12 months or longer

No definition available.

Name:	tmk_AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions12MonthsOrLonger
Namespace Prefix:	tmk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant