Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 01, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		165,921,158
Entity Central Index Key	0000036270
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Transition Report	false
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 RateNon-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 7.500% Non-Cumulative Preferred Stock, Series J
Trading Symbol	MTBPrJ
Security Exchange Name	NYSE