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v3.25.1

Segment Information - Additional Information (Details) | 3 Months Ended
--- | ---
Mar. 31, 2024 USD ($)
Segment Reporting [Abstract] |
Taxable-equivalent adjustment | $ 12,000,000

X
- Definition Taxable equivalent adjustment. + References No definition available. + Details
Name: | mtb_TaxableEquivalentAdjustment
Namespace Prefix: | mtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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