Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2024	Feb. 14, 2025	Jun. 30, 2024
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2024
Entity File Number	1-9861
Entity Registrant Name	M&T BANK CORPORATION
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	16-0968385
Entity Address, Address Line One	One M&T Plaza
Entity Address, City or Town	Buffalo
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14203
City Area Code	716
Local Phone Number	635-4000
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 24,606,656,349
Entity Common Stock, Shares Outstanding		164,333,454
Documents Incorporated by Reference	Portions of the Proxy Statement for the 2025 Annual Meeting of Shareholders of M&T Bank Corporation in Parts II and III.
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Entity Central Index Key	0000036270
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.50 par value
Trading Symbol	MTB
Security Exchange Name	NYSE
Series H Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Perpetual Fixed-to-Floating Rate Non-Cumulative Preferred Stock, Series H
Trading Symbol	MTBPrH
Security Exchange Name	NYSE
Series J Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Perpetual Fixed Rate Non-Cumulative Preferred Stock, Series J
Trading Symbol	MTBPrJ
Security Exchange Name	NYSE