XML 238 R202.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Employee Benefit Plans (Actual & Target Allocation of Fair Value by Asset Class) (Details) - UNITED STATES | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Pension Benefits |  |
Actual weighted average asset allocation by major asset class for the Invested Plans [Abstract] |  |
Actual | 100.00% | 100.00%
Pension Benefits | Fixed maturity securities AFS |  |
Actual weighted average asset allocation by major asset class for the Invested Plans [Abstract] |  |
Target | 85.00% |
Actual | 83.00% | 82.00%
Pension Benefits | Equity Securities |  |
Actual weighted average asset allocation by major asset class for the Invested Plans [Abstract] |  |
Target | 7.00% |
Actual | 7.00% | 6.00%
Pension Benefits | Alternative Securities |  |
Actual weighted average asset allocation by major asset class for the Invested Plans [Abstract] |  |
Target | 8.00% |
Actual | 10.00% | 12.00%
Other Postretirement Benefits |  |
Actual weighted average asset allocation by major asset class for the Invested Plans [Abstract] |  |
Actual | 100.00% | 100.00%
Other Postretirement Benefits | Fixed maturity securities AFS |  |
Actual weighted average asset allocation by major asset class for the Invested Plans [Abstract] |  |
Target | 95.00% |
Actual | 94.00% | 94.00%
Other Postretirement Benefits | Equity Securities |  |
Actual weighted average asset allocation by major asset class for the Invested Plans [Abstract] |  |
Target | 5.00% |
Actual | 6.00% | 6.00%
Other Postretirement Benefits | Alternative Securities |  |
Actual weighted average asset allocation by major asset class for the Invested Plans [Abstract] |  |
Target | 0.00% |
Actual | 0.00% | 0.00%

X
- References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanInformationAboutPlanAssetsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanSponsorLocationAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=met_AlternativeSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |