XML 85 R74.htm IDEA: XBRL DOCUMENT
v3.25.2

Variable interest entities and asset securitizations - Summary of Carrying Amount (Details) - Variable Interest Entity Primary Beneficiary - USD ($) $ in Millions | Jun. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Affordable Housing Projects |  |
Variable Interest Entity [Line Items] |  |
Investment in partnership carrying amount | $ 1,527 | $ 1,384
Unfunded commitments includes carrying amount of its investments | 596 | 467
Contingent commitments to provide additional capital contributions to partnerships | 83 | 69
Renewable Energy |  |
Variable Interest Entity [Line Items] |  |
Investment in partnership carrying amount | 104 | 135
Unfunded commitments includes carrying amount of its investments | 101 | 46
Other Projects |  |
Variable Interest Entity [Line Items] |  |
Investment in partnership carrying amount | 35 | 37
Unfunded commitments includes carrying amount of its investments | $ 0 | $ 0

X
- Definition Contingent Commitments to Provide Additional Capital Contributions to Partnerships + References No definition available. + Details
Name: | mtb_ContingentCommitmentsToProvideAdditionalCapitalContributionsToPartnerships
Namespace Prefix: | mtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The carrying amount of investments in variable interest entity. + References No definition available. + Details
Name: | mtb_InvestmentsInVariableInterestEntityCarryingAmount
Namespace Prefix: | mtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unfunded commitments includes carrying amount of its investments. + References No definition available. + Details
Name: | mtb_UnfundedCommitmentsIncludesCarryingAmountOfItsInvestments
Namespace Prefix: | mtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481203/810-10-50-3 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 25 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-25 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (bb) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481203/810-10-50-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 25 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-25 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (b)(1)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A + Details
Name: | us-gaap_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_OtherCommitmentsAxis=mtb_AffordableHousingProjectsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_OtherCommitmentsAxis=mtb_RenewableEnergyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_OtherCommitmentsAxis=mtb_OtherProjectsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |