XML 125 R103.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Market Risk Benefits - Rollforward (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Market Risk Benefit [Line Items] |  |  |
Beginning balance | $ 3,483 |  |
Effect of changes in capital markets | 658 | $ 3,347 | $ 839
Ending balance | 2,893 | 3,483 |
Retirement Assurance | Asia |  |  |
Market Risk Benefit [Line Items] |  |  |
Beginning balance | 226 | 277 | 318
Balance, beginning of period, before effect of cumulative changes in the instrument-specific credit risk | 233 | 284 | 326
Attributed fees collected | 3 | 3 | 4
Benefit payments | (12) | 0 | (7)
Effect of changes in interest rates | 1 | (25) | (6)
Effect of changes in equity index volatility | 0 | 0 | (3)
Actual policyholder behavior different from expected behavior | (1) | 6 | (16)
Effect of changes in future expected policyholder behavior and other assumptions | (1) | 5 | 0
Effect of foreign currency translation and other, net | (18) | (40) | (14)
Balance, beginning of period, before effect of cumulative changes in the instrument-specific credit risk | 205 | 233 | 284
Cumulative effect of changes in the instrument-specific credit risk | (2) | (8) | (8)
Effect of foreign currency translation on the cumulative instrument-specific credit risk | 0 | 1 | 1
Ending balance | 203 | 226 | 277
Retirement Assurance | Asia | At annuitization or exercise of other living benefits |  |  |
Market Risk Benefit [Line Items] |  |  |
Net amount at risk | $ 119 | $ 127 | $ 119
Average attained age of policyholders | 58 years | 58 years | 57 years
Variable Annuity | MetLife Holdings |  |  |
Market Risk Benefit [Line Items] |  |  |
Beginning balance | $ 3,225 | $ 5,929 | $ 7,001
Balance, beginning of period, before effect of cumulative changes in the instrument-specific credit risk | 3,360 | 6,229 | 7,055
Attributed fees collected | 377 | 387 | 413
Benefit payments | (58) | (42) | (41)
Effect of changes in interest rates | (161) | (3,610) | (536)
Effect of changes in capital markets | (900) | 861 | (1,163)
Effect of changes in equity index volatility | (135) | 38 | 25
Actual policyholder behavior different from expected behavior | 144 | 20 | (92)
Effect of changes in future expected policyholder behavior and other assumptions | 9 | (328) | 563
Effect of foreign currency translation and other, net | 152 | 36 | 350
Effect of changes in risk margin | (16) | (231) | (345)
Balance, beginning of period, before effect of cumulative changes in the instrument-specific credit risk | 2,772 | 3,360 | 6,229
Cumulative effect of changes in the instrument-specific credit risk | (54) | (130) | (304)
Effect of foreign currency translation on the cumulative instrument-specific credit risk | 4 | (5) | 4
Ending balance | 2,722 | 3,225 | 5,929
Variable Annuity | MetLife Holdings | In the event of death |  |  |
Market Risk Benefit [Line Items] |  |  |
Net amount at risk | $ 2,828 | $ 4,387 | $ 1,131
Average attained age of policyholders | 70 years | 69 years | 70 years
Variable Annuity | MetLife Holdings | At annuitization or exercise of other living benefits |  |  |
Market Risk Benefit [Line Items] |  |  |
Net amount at risk | $ 675 | $ 1,141 | $ 565
Average attained age of policyholders | 70 years | 71 years | 68 years
Insurance, Other |  |  |
Market Risk Benefit [Line Items] |  |  |
Beginning balance | $ 32 | $ 491 | $ 582
Balance, beginning of period, before effect of cumulative changes in the instrument-specific credit risk | 24 | 539 | 619
Attributed fees collected | 34 | 61 | 72
Benefit payments | (28) | (4) | (2)
Effect of changes in interest rates | (3) | (499) | (227)
Effect of changes in capital markets | (41) | 139 | (110)
Effect of changes in equity index volatility | (6) | 31 | 4
Actual policyholder behavior different from expected behavior | (22) | (12) | 29
Effect of changes in future expected policyholder behavior and other assumptions | 2 | (1) | 56
Effect of foreign currency translation and other, net | (9) | (224) | 100
Effect of changes in risk margin | (1) | (6) | (2)
Balance, beginning of period, before effect of cumulative changes in the instrument-specific credit risk | (50) | 24 | 539
Cumulative effect of changes in the instrument-specific credit risk | 17 | 7 | (49)
Effect of foreign currency translation on the cumulative instrument-specific credit risk | 1 | 1 | 1
Ending balance | (32) | 32 | 491
Less: Reinsurance recoverable | 18 | 23 | 33
Balance, end of period, net of reinsurance | $ (50) | $ 9 | $ 458

X
- Definition Amount, before tax, of accumulated other comprehensive income (loss) (AOCI) from (increase) decrease in instrument-specific credit risk on contract or contract feature in long-duration contract issued by insurance entity protecting contract holder from other-than-nominal capital market risk and exposing insurance entity to other-than-nominal capital market risk. + References No definition available. + Details
Name: | met_AOCIMarketRiskBenefitForeignCurrencyTranslationInstrumentSpecificCreditRiskBeforeTax
Namespace Prefix: | met_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Market Risk Benefit Increase (Decrease) From Risk Margin + References No definition available. + Details
Name: | met_MarketRiskBenefitIncreaseDecreaseFromRiskMargin
Namespace Prefix: | met_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, before tax, of accumulated other comprehensive income (loss) (AOCI) from (increase) decrease in instrument-specific credit risk on contract or contract feature in long-duration contract issued by insurance entity protecting contract holder from other-than-nominal capital market risk and exposing insurance entity to other-than-nominal capital market risk. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13K -Subparagraph (k) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-13K + Details
Name: | us-gaap_AociMarketRiskBenefitInstrumentSpecificCreditRiskBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before effect of reinsurance and after accumulated increase (decrease) in instrument-specific credit risk, of contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480112/944-40-45-3 + Details
Name: | us-gaap_MarketRiskBenefitAfterIncreaseDecreaseFromInstrumentSpecificCreditRisk
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after effect of reinsurance and cumulative increase (decrease) in instrument-specific credit risk, of contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B + Details
Name: | us-gaap_MarketRiskBenefitAfterReinsuranceAndCumulativeIncreaseDecreaseFromInstrumentSpecificCreditRiskChange
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of cash inflow to contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk from attributed fee collected. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13K -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-13K + Details
Name: | us-gaap_MarketRiskBenefitAttributedFeeCollected
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, before effect of reinsurance and cumulative increase (decrease) in instrument-specific credit risk, of contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B + Details
Name: | us-gaap_MarketRiskBenefitBeforeReinsuranceAndCumulativeIncreaseDecreaseFromInstrumentSpecificCreditRiskChange
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of cash outflow to policyholder from benefit payment for contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13K -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-13K + Details
Name: | us-gaap_MarketRiskBenefitBenefitPayment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase (decrease) in contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk from change associated with actual policyholder behavior different from expected. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13K -Subparagraph (h) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-13K + Details
Name: | us-gaap_MarketRiskBenefitIncreaseDecreaseFromActualPolicyholderBehaviorDifferentFromExpected
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase (decrease) in contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk from change in equity market assumption. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13K -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-13K + Details
Name: | us-gaap_MarketRiskBenefitIncreaseDecreaseFromEquityMarketChange
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase (decrease) in contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk from change in future expected policyholder behavior assumption. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13K -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-13K + Details
Name: | us-gaap_MarketRiskBenefitIncreaseDecreaseFromFutureExpectedPolicyholderBehaviorAssumption
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase (decrease) in contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk from change in interest rate. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13K -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-13K + Details
Name: | us-gaap_MarketRiskBenefitIncreaseDecreaseFromInterestRateChange
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase (decrease) in contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk from change in market volatility assumption. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480016/944-40-65-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 13K -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-13K + Details
Name: | us-gaap_MarketRiskBenefitIncreaseDecreaseFromVolatility
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B + Details
Name: | us-gaap_MarketRiskBenefitLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of guaranteed benefit in excess of current account balance of contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B + Details
Name: | us-gaap_MarketRiskBenefitNetAmountAtRisk
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after allowance for credit loss, recoverable under reinsurance for contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 29G -Publisher FASB -URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 7B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B + Details
Name: | us-gaap_MarketRiskBenefitReinsuranceRecoverableAfterAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Weighted average attained age of policyholders or contract holders in the specified guarantee type and subset of guarantee class, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479808/944-20-55-15 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph ((d)(5)) -SubTopic 80 -Topic 944 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480109/944-80-50-1 + Details
Name: | us-gaap_NetAmountAtRiskByProductAndGuaranteeWeightedAverageAttainedAge1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cumulative translation gain (loss), before tax, from translating foreign currency financial statements into the reporting currency. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482790/220-10-45-11 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 20 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481694/830-30-45-20 + Details
Name: | us-gaap_TranslationAdjustmentFunctionalToReportingCurrencyIncreaseDecreaseGrossOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_ProductOrServiceAxis=met_RetirementAssuranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=met_AsiaSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteedInsuranceContractTypeOfBenefitAxis=us-gaap_AnnuitizationBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_VariableAnnuityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=met_MetLifeHoldingsSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteedInsuranceContractTypeOfBenefitAxis=us-gaap_GuaranteedMinimumDeathBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_OtherInsuranceProductLineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |