This represents the recorded investment for impaired mortgage loans held-for-investment.

No definition available.

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

- Definition

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.

+ References

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

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5258-111524

+ Details

Name:	us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953550-111524

+ Details

Name:	us-gaap_ImpairedFinancingReceivableRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_LoanAndLeaseReceivablesImpairedAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Investments (Impaired Mortgage Loans) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Impaired Mortgage Loans
Unpaid Principal Balance	$ 633	$ 750
Valuation allowances	322	347	481	664
Recorded Investment	556	616
Average Investment	693	681
Interest Income	24	22
Loans with a Valuation Allowance [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	294	568
Recorded Investment	288	556
Valuation allowances	66	117
Recorded Investment	222	439
Loans Without Valuation Allowances [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	339	182
Recorded Investment	334	177
Commercial mortgage loans portfolio segment [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	513	548
Valuation allowances	258	293	398	562
Recorded Investment	448	445
Average Investment	526	464
Interest Income	15	14
Commercial mortgage loans portfolio segment [Member] \| Loans with a Valuation Allowance [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	214	445
Recorded Investment	210	436
Valuation allowances	58	94
Recorded Investment	152	342
Commercial mortgage loans portfolio segment [Member] \| Loans Without Valuation Allowances [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	299	103
Recorded Investment	296	103
Agricultural [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	103	189
Valuation allowances	44	52	81	88
Recorded Investment	93	160
Average Investment	153	204
Interest Income	9	8
Agricultural [Member] \| Loans with a Valuation Allowance [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	68	110
Recorded Investment	66	107
Valuation allowances	7	21
Recorded Investment	59	86
Agricultural [Member] \| Loans Without Valuation Allowances [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	35	79
Recorded Investment	34	74
Residential [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	17	13
Valuation allowances	20	2	2	14
Recorded Investment	15	11
Average Investment	14	13
Interest Income	0	0
Residential [Member] \| Loans with a Valuation Allowance [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	12	13
Recorded Investment	12	13
Valuation allowances	1	2
Recorded Investment	11	11
Residential [Member] \| Loans Without Valuation Allowances [Member]
Impaired Mortgage Loans
Unpaid Principal Balance	5	0
Recorded Investment	$ 4	$ 0