XML 80 R69.htm IDEA: XBRL DOCUMENT
v3.25.2

Derivative financial instruments - Information about Fair Values of Derivative Instruments in Consolidated Balance Sheet (Detail) - USD ($) $ in Millions | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2025 | Dec. 31, 2024
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | $ 265 | $ 255
Liability derivatives, fair value | 554 | 822
Reduction in estimated fair value of interest rate contracts in asset position | (440) | (686)
Reduction in estimated fair value of interest rate contracts in liability position | (32) | (15)
Fair value hedges: |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 194 | 206
Liability derivatives, fair value | 518 | 787
Fair value hedges: | Designated as Hedging Instrument |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 27 | 6
Liability derivatives, fair value | 4 | 3
Fair value hedges: | Not Designated as Hedging Instrument |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 44 | 43
Liability derivatives, fair value | 32 | 32
Interest rate swap agreements | Fair value hedges: | Designated as Hedging Instrument |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 24 | 2
Liability derivatives, fair value | 0 | 3
Commitments to sell real estate loans | Fair value hedges: | Designated as Hedging Instrument |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 3 | 4
Liability derivatives, fair value | 4 | 0
Commitments to sell real estate loans | Fair value hedges: | Not Designated as Hedging Instrument |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 27 | 39
Liability derivatives, fair value | 7 | 0
Commitments to originate real estate loans for sale | Fair value hedges: | Not Designated as Hedging Instrument |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 17 | 4
Liability derivatives, fair value | 25 | 32
Interest Rate Contracts | Fair value hedges: | Not Designated as Hedging Instrument |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 168 | 185
Liability derivatives, fair value | 493 | 769
Foreign exchange and other option and futures contracts | Fair value hedges: | Not Designated as Hedging Instrument |  |
Derivatives, Fair Value [Line Items] |  |
Asset derivatives, fair value | 26 | 21
Liability derivatives, fair value | $ 25 | $ 18

X
- Definition Increase (decrease) in estimated fair value of interest rate contracts in asset position. + References No definition available. + Details
Name: | mtb_IncreaseDecreaseInEstimatedFairValueOfInterestRateContractsInAssetPosition
Namespace Prefix: | mtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Increase (decrease) in estimated fair value of interest rate contracts in liability position. + References No definition available. + Details
Name: | mtb_IncreaseDecreaseInEstimatedFairValueOfInterestRateContractsInLiabilityPosition
Namespace Prefix: | mtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7A -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-7A Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-22 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 21 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-21 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 20 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-20 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-15 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483466/210-20-50-3 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (c)(2) -SubTopic 20 -Topic 860 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481326/860-20-50-4D + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7A -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-7A Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-22 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 21 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-21 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 20 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-20 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-15 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483466/210-20-50-3 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (c)(2) -SubTopic 20 -Topic 860 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481326/860-20-50-4D + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix: | us-gaap_
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/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 182 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-182 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A + Details
Name: | us-gaap_DerivativesFairValueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_FairValueHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mtb_CommitmentsToSellRealEstateLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mtb_MortgageRelatedCommitmentsToOriginateRealEstateLoansForSaleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mtb_ForeignExchangeAndOtherOptionAndFuturesContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |