Name:	met_CommercialMortgageLoansHeldByConsolidatedSecuritizationEntitiesFairValueOption
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The balance represents the amount of loans that are secured by real estate mortgages.

No definition available.

Name:	met_MortgageLoansHeldForInvestment
Namespace Prefix:	met_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	met_MortgageLoansHeldForSaleAbstract
Namespace Prefix:	met_
Data Type:	xbrli:stringItemType
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Period Type:	duration

Percentage of Allowance For Loan And Lease Losses on Real Estate to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfAllowanceForLoanAndLeaseLossesRealEstateToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
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Period Type:	instant

Percentage of Commercial Mortgage Loans Held By Consolidated Securitization Entities Fair Value Option to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfCommercialMortgageLoansHeldByConsolidatedSecuritizationEntitiesFairValueOptionToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of Consumer Mortgage Loans and Leases Receivable to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfLoansAndLeasesReceivableConsumerMortgageToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of Loans Held For Sale, Mortgages to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfLoansHeldForSaleMortgagesToMortgagesLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of Loans Held For Sale, Other to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfLoansHeldForSaleOtherToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
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Percentage of Commercial Agricultural Loans Receivable to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfLoansReceivableCommercialAgriculturalToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
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Period Type:	instant

Percentage of Commercial Mortgage Loans Receivable to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfLoansReceivableCommercialMortgageToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
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Period Type:	instant

Percentage of Loans Receivable Held For Sale, Net to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfLoansReceivableHeldForSaleNetToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
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Percentage of Mortgage Loans Held-for-investment, net to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfMortgageLoansHeldForInvestmentNetToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of Mortgage Loans Held For Investment to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfMortgageLoansHeldForInvestmentToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of Commercial Agricultural Loans Receivable to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfMortgageLoansOnRealEstateCommercialAndConsumerNetToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of Mortgage Loans On Real Estate to total Mortgage Loans on Real Estate.

No definition available.

Name:	met_PercentageOfMortgageLoansOnRealEstateToMortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	met_
Data Type:	num:percentItemType
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Percentage of securitized reverse residential mortgage loans to mortgage loans on real estate commercial and consumer, net.

No definition available.

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Namespace Prefix:	met_
Data Type:	num:percentItemType
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Period Type:	instant

This caption presents the carrying value of mortgage loans held as securitized reverse residential mortgage loans for which the Company has elected the fair value option.

No definition available.

Name:	met_SecuritizedReverseResidentialMortgageLoansFairValueOption
Namespace Prefix:	met_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 60

-Paragraph 47

-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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 45

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The gross carrying amount of mortgage loans to individuals. This item excludes subordinated loans such as home equity lines of credit.

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

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Chapter V

-Section 563c.102

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-Name Audit and Accounting Guide (AAG)

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-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.

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Reflects the aggregate carrying amount of all categories of loans and leases held in portfolio, net of unearned income and the allowance for losses on loans and leases.

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

-Publisher AICPA

-Name Statement of Position (SOP)

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-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 310

-SubTopic 10

-Section 45

-Paragraph 2

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-Name Accounting Standards Codification

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Carrying amount of mortgage loans to individuals not classified as held for investment but are held-for-sale.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

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-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Name Federal Regulation (FR)

-Number Title 12

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-Section 563c.102

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-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Permanent Investor

-URI http://asc.fasb.org/extlink&oid=6520390

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 65

-Paragraph 1, 34

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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-Section 45

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Name:	us-gaap_LoansHeldForSaleMortgages
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Reflects the carrying amount of loans held for sale not otherwise specified in the existing taxonomy.

Name:	us-gaap_LoansHeldForSaleOther
Namespace Prefix:	us-gaap_
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This element represents the gross carrying amount of agricultural loans receivable as of the balance sheet date. In general, agricultural loans consist of borrowings used to finance major equipment and machinery purchases and expenses, livestock or crop production (including fisheries), and to supplement working capital needs of an entity engaged in farming operations.

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Reflects the gross carrying amount of unpaid loans issued to businesses to provide financing on existing land or a building, which, pursuant to terms of the underlying debt instrument, are secured at a minimum but possibly exclusively by that real property. Mortgages represent permanent financing, and are issued to replace previously existing mortgages or pay off acquisition, development and construction loans, or to provide cash to the borrower.

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

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-Name Accounting Standards Codification

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 9

-Section 03

-Paragraph 7

-Subparagraph a

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-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

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-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.

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The aggregate carrying amount of loans receivable that will be sold to other entities. Includes mortgage and all other loans (collectively, loans) not classified as held for investment. Such loans are stated at the lower of cost or market, or elected fair value. Mortgage loans exclude mortgage-backed securities which are considered a debt security (other loan).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

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-Subparagraph (SX 210.9-03.7(a))

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-Publisher AICPA

-Name Statement of Position (SOP)

-Number 01-6

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-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 Statement of Financial Accounting Standard (FAS)

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-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.

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-Name Accounting Standards Codification

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 9

-Section 03

-Paragraph 7

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-Name Accounting Standards Codification

-Topic 948

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-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Chapter V

-Section 563c.102

-Subsection I

-Paragraph 8

-Subparagraph h

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 65

-Paragraph 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.

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-Name Accounting Standards Codification

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Total carrying amount of mortgage loans as of the balance sheet date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

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-Subparagraph (SX 210.12-29.6)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

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The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 60

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-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

-Article 7

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-Paragraph 1

-Subparagraph c

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

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-Paragraph 1

-Subparagraph (SX 210.7-03.1(c))

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