Amortized cost of investment in fixed maturities rated below investment grade

No definition available.

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- Definition

Fair Value Of Investment In Fixed Maturities Rated Below Investment Grade

+ References

No definition available.

+ Details

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- Definition

Investment in low-income housing tax entities, carrying value.

+ References

No definition available.

+ Details

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- Definition

Lease term in years.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Letter of Credit Facilities, Maximum Borrowing Capacity

+ References

No definition available.

+ Details

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- Definition

Par value of investment in fixed maturities rated below investment grade

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Percentage of invested assets rated below investment grade

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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- Definition

Purchase Commitments Under Low-Income Housing Program

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Purchase Commitments Under Low Income Housing Program Due In Second Year

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Purchase Commitments Under Low Income Housing Program Due In Third Year

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Purchase Commitments Under Low Income Housing Program Due Thereafter

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Purchase Commitments Under Low Income Housing Program Due Within One Year

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reinsurance assumed ratio on premium income

+ References

No definition available.

+ Details

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Namespace Prefix:	tmk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Retention limits per life

+ References

No definition available.

+ Details

Name:	tmk_RetentionLimitsPerLife
Namespace Prefix:	tmk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

State and municipal government securities at fair value invested by state.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio of insurance contracts that are subject to reinsurance participation to all contracts in force.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 45

-Paragraph 13

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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Balance Type:	credit
Period Type:	instant

- Definition

Life insurance assumed from another insurer divided by gross life insurance in force.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 05

-Paragraph c

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects when the credit facility terminates, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Data Type:	us-types:dateStringItemType
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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within one year of the balance sheet date relating to leases defined as operating.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 122

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 16

-Subparagraph b(i)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 55

-Paragraph 40

-Subparagraph (Note 3)

-URI http://asc.fasb.org/extlink&oid=6584154&loc=d3e38371-112697

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41502-112717

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fifth year of the balance sheet date relating to leases defined as operating.

+ References

+ Details

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fourth year of the balance sheet date relating to leases defined as operating.

+ References

+ Details

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the third year of the balance sheet date relating to leases defined as operating.

+ References

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the second year of the balance sheet date relating to leases defined as operating.

+ References

+ Details

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due after the fifth year from the balance sheet date on leases defined as operating.

+ References

+ Details

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- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41499-112717

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Balance Type:	debit
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- Definition

Ratio of premium income to reinsurance.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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Commitments And Contingencies (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Commitments and Contingencies [Line Items]
Retention limits per life	$ 2.0
Percentage of insurance ceded on total life insurance in force	0.50%
Percentage of insurance ceded on premium income	0.30%
Life reinsurance assumed rate on life insurance in force	3.00%
Reinsurance assumed ratio on premium income	1.20%
Rental expense for operating leases	4.8	4.9	4.9
Future minimum rental commitments in 2012	2.7
Future minimum rental commitments in 2013	2.4
Future minimum rental commitments in 2014	2.0
Future minimum rental commitments in 2015	2.0
Future minimum rental commitments in 2016	1.4
Future minimum rental commitments in aggregate	13.2
Investment in low-income housing interests	293	283
Purchase commitments under low income housing program		109
Purchase commitments under low income housing program 2012		85
Purchase commitments under low income housing program 2013		21
Purchase commitments under low income housing program 2014		2
Purchase commitments under low income housing program thereafter		1
Par value of investment in fixed maturities rated below investment grade	787
Amortized cost of investment in fixed maturities rated below investment grade	701
Fair value of investment in fixed maturities rated below investment grade	579
Percentage of invested assets rated below investment grade	5.00%
Letters of credit facility expiration date	2015
Letters of credit maximum borrowing capacity	250
Leases Commenced In 2003 [Member]
Commitments and Contingencies [Line Items]
Lease term in years	10
Leases Commenced In 2009 [Member]
Commitments and Contingencies [Line Items]
Lease term in years	10
Lease [Member] \| Guarantees [Member]
Commitments and Contingencies [Line Items]
Maximum guarantee	8
Trust Preferred Securities [Member]
Commitments and Contingencies [Line Items]
Maximum guarantee	120
Letters of Credit [Member] \| Guarantees [Member]
Commitments and Contingencies [Line Items]
Maximum guarantee	$ 198
Texas [Member]
Commitments and Contingencies [Line Items]
State and municipal government securities at fair value invested by state	34.00%
Ohio [Member]
Commitments and Contingencies [Line Items]
State and municipal government securities at fair value invested by state	8.00%
Washington [Member]
Commitments and Contingencies [Line Items]
State and municipal government securities at fair value invested by state	7.00%
Alabama [Member]
Commitments and Contingencies [Line Items]
State and municipal government securities at fair value invested by state	5.00%