XML 57 R46.htm IDEA: XBRL DOCUMENT
v3.25.2

Loans and allowance for loan losses - Summary of Current, Past Due and Nonaccrual Loans (Detail) - USD ($) $ in Millions | Jun. 30, 2025 | Mar. 31, 2025 | Jan. 01, 2025 | Dec. 31, 2024 | Jun. 30, 2024 | Mar. 31, 2024 | Jan. 01, 2024
--- | --- | --- | --- | --- | --- | --- | ---
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | $ 1,573 | $ 1,540 | $ 1,690 | $ 1,690 | $ 2,024 | $ 2,302 | $ 2,166
Total | [1] | 136,116 |  |  | 135,581 |  |  |
Unamortized loan cost (fee) and purchase premium (discount) |  | (301) |  |  | 277 |  |  |
Financing receivable, accrued interest, before allowance for credit loss |  | 617 |  |  | 628 |  |  |
Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 132,679 |  |  | 131,898 |  |  |
30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 1,368 |  |  | 1,655 |  |  |
Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 496 |  |  | 338 |  |  |
Commercial and industrial |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 787 | 662 | 696 | 696 | 805 | 864 | 670
Total |  | 61,660 |  |  | 61,481 |  |  |
Commercial and industrial | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 60,632 |  |  | 60,374 |  |  |
Commercial and industrial | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 219 |  |  | 399 |  |  |
Commercial and industrial | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 22 |  |  | 12 |  |  |
Commercial Real Estate | Commercial |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 376 | 394 | 468 | 468 | 707 | 855 | 869
Total |  | 20,155 |  |  | 20,780 |  |  |
Mortgage loans held for sale |  | 361 |  |  | 310 |  |  |
Commercial Real Estate | Commercial | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 19,447 |  |  | 20,054 |  |  |
Commercial Real Estate | Commercial | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 321 |  |  | 255 |  |  |
Commercial Real Estate | Commercial | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 11 |  |  | 3 |  |  |
Commercial Real Estate | Residential builder and developer |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 1 | 1 | 2 | 2 | 2 | 3 | 3
Total |  | 151 |  |  | 835 |  |  |
Mortgage loans held for sale |  | 661 |  |  |  |  |  |
Commercial Real Estate | Residential builder and developer | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 150 |  |  | 830 |  |  |
Commercial Real Estate | Residential builder and developer | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 0 |  |  | 3 |  |  |
Commercial Real Estate | Residential builder and developer | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 0 |  |  | 0 |  |  |
Commercial Real Estate | Other commercial construction |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 23 | 28 | 66 | 66 | 77 | 141 | 171
Total |  | 4,261 |  |  | 5,149 |  |  |
Commercial Real Estate | Other commercial construction | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 4,199 |  |  | 5,018 |  |  |
Commercial Real Estate | Other commercial construction | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 35 |  |  | 65 |  |  |
Commercial Real Estate | Other commercial construction | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 4 |  |  | 0 |  |  |
Commercial Real Estate | Other Revenue Portfolio Segment |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Mortgage loans held for sale |  | 15 |  |  |  |  |  |
Residential Real Estate | Residential |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 265 | 284 | 279 | 279 | 260 | 255 | 270
Total |  | 24,117 |  |  | 23,166 |  |  |
Mortgage loans held for sale |  | 222 |  |  | 211 |  |  |
Residential Real Estate | Residential | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 22,796 |  |  | 21,853 |  |  |
Total |  | 22,796 |  |  | 21,853 |  |  |
Residential Real Estate | Residential | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 606 |  |  | 719 |  |  |
Residential Real Estate | Residential | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 450 |  |  | 315 |  |  |
Total |  | 450 |  |  | 315 |  |  |
Consumer | Home equity lines and loans |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 75 | 78 | 81 | 81 | 79 | 87 | 81
Total |  | 4,634 |  |  | 4,592 |  |  |
Consumer | Home equity lines and loans | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 4,530 |  |  | 4,482 |  |  |
Total |  | 4,530 |  |  | 4,482 |  |  |
Consumer | Home equity lines and loans | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 29 |  |  | 29 |  |  |
Consumer | Home equity lines and loans | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 0 |  |  | 0 |  |  |
Total |  | 0 |  |  | 0 |  |  |
Consumer | Recreational finance |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 25 | 26 | 31 | 31 | 25 | 30 | 36
Total |  | 13,666 |  |  | 12,564 |  |  |
Consumer | Recreational finance | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 13,555 |  |  | 12,429 |  |  |
Total |  | 13,555 |  |  | 12,429 |  |  |
Consumer | Recreational finance | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 86 |  |  | 104 |  |  |
Consumer | Recreational finance | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 0 |  |  | 0 |  |  |
Total |  | 0 |  |  | 0 |  |  |
Consumer | Automobile |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 9 | 11 | 12 | 12 | 11 | 13 | 14
Total |  | 5,260 |  |  | 4,794 |  |  |
Consumer | Automobile | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 5,199 |  |  | 4,724 |  |  |
Total |  | 5,199 |  |  | 4,724 |  |  |
Consumer | Automobile | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 52 |  |  | 58 |  |  |
Consumer | Automobile | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 0 |  |  | 0 |  |  |
Total |  | 0 |  |  | 0 |  |  |
Consumer | Other |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Amortized Cost |  | 12 | $ 56 | $ 55 | 55 | $ 58 | $ 54 | $ 52
Total |  | 2,212 |  |  | 2,220 |  |  |
Consumer | Other | Current |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 2,171 |  |  | 2,134 |  |  |
Consumer | Other | 30-89 Days Past Due |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | 20 |  |  | 23 |  |  |
Consumer | Other | Accruing Loans Past Due 90 Days or More |  |  |  |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |  |  |  |
Loans |  | $ 9 |  |  | $ 8 |  |  |
[1] | Loans of $2.5 billion and $1.5 billion at June 30, 2025 and December 31, 2024, respectively, were held in special purpose trusts to settle the respective obligations of asset-backed notes issued by those trusts. The outstanding balances of those asset-backed notes issued to third party investors were included in Long-term borrowings and were $2.1 billion at June 30, 2025 and $1.2 billion at December 31, 2024.

X
- Definition Amount, before allowance for credit loss, of accrued interest on financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 16 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-16 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 9: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 10: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-14 Reference 12: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (e)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 13: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (e)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 14: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 15: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 16: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 17: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 80 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-80 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of unamortized loan commitment, origination, and other costs (fees) and purchase premium (discount) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 310 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481598/310-20-45-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-4 Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 3 -SubTopic 20 -Topic 310 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481569/310-20-50-3 + Details
Name: | us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after valuation allowance, of financing receivable held for sale and not part of disposal group. Excludes loan covered under loss sharing agreement and loan classified as investment in debt security. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481990/310-10-45-2 + Details
Name: | us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetNotPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mtb_CommercialRealEstateExcludingResidentialBuilderAndDeveloperAndOtherConstructionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mtb_ResidentialBuilderAndDeveloperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mtb_OtherCommercialConstructionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mtb_OtherRevenuePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mtb_ResidentialRealEstateExcludingAltAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mtb_HomeEquityLinesAndLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mtb_RecreationalFinanceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_AutomobileLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |