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

No definition available.

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

No definition available.

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

No definition available.

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Percentage of loans and leases receivable consumer other to total mortgage loans on real estate.

No definition available.

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

No definition available.

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

No definition available.

Name:	met_PercentageOfLoansReceivableHeldForSaleNetToMortgageLoansOnRealEstateCommercialAndConsumerNet
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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
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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
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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
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Period Type:	instant

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

No definition available.

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Namespace Prefix:	met_
Data Type:	num:percentItemType
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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 Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6873192&loc=d3e21338-158488

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Amount before allowance of consumer mortgage. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes subordinated loans such as home equity lines of credit and loans and leases covered under loss sharing agreements.

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Amount before allowance of consumer loans and leases not otherwise specified in the taxonomy. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Amount before allowance of loans issued to agricultural institutions. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5066-111524

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-Name Regulation S-X (SX)

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Amount before allowance of mortgage loans on existing land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5066-111524

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Amount classified as loans attributable to disposal group held for sale or disposed of. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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

-Publisher FASB

-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 205

-SubTopic 10

-Section S99

-Paragraph 6

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

-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

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

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-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

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

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-Name Regulation S-X (SX)

-Number 210

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-Name Accounting Standards Codification

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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 Accounting Standards Codification

-Topic 944

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-Subparagraph (SX 210.7-03.1(c))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph c

-Article 7