XML 19 R46.htm IDEA: XBRL DOCUMENT v2.4.1.9
Loans and Leases and the Allowance for Credit Losses - Impaired Loans and Leases (Detail) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance $ 470,539us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment $ 498,575us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Unpaid Principal Balance With Related Allowance 549,137us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance 581,887us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
Related Allowance 70,582us-gaap_ImpairedFinancingReceivableRelatedAllowance 82,643us-gaap_ImpairedFinancingReceivableRelatedAllowance
Recorded Investment With No Related Allowance 292,315us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment 263,880us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
Unpaid Principal Balance With No Related Allowance 408,326us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance 371,907us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
Recorded Investment 762,854us-gaap_ImpairedFinancingReceivableRecordedInvestment 762,455us-gaap_ImpairedFinancingReceivableRecordedInvestment
Unpaid Principal Balance 957,463us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance 953,794us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Related Allowance 70,582us-gaap_ImpairedFinancingReceivableRelatedAllowance 82,643us-gaap_ImpairedFinancingReceivableRelatedAllowance
Commercial, Financial, Leasing, etc. [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 108,870us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember		 132,340us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember
Unpaid Principal Balance With Related Allowance 130,029us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember		 165,146us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember
Related Allowance 19,335us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember		 31,779us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember
Recorded Investment With No Related Allowance 116,325us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember		 73,978us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember
Unpaid Principal Balance With No Related Allowance 135,534us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember		 81,493us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember
Recorded Investment 225,195us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember		 206,318us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember
Unpaid Principal Balance 265,563us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember		 246,639us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember
Related Allowance 19,335us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember		 31,779us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_CommercialFinancialLeasingMember
Commercial Real Estate [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 99,729us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember		 83,955us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Unpaid Principal Balance With Related Allowance 122,098us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember		 96,209us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Related Allowance 15,836us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember		 14,121us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Recorded Investment With No Related Allowance 51,734us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember		 66,777us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Unpaid Principal Balance With No Related Allowance 59,235us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember		 78,943us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Recorded Investment 151,463us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember		 150,732us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Unpaid Principal Balance 181,333us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember		 175,152us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Related Allowance 15,836us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember		 14,121us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Residential Builder and Developer [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 6,512us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember		 17,632us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember
Unpaid Principal Balance With Related Allowance 8,731us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember		 22,044us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember
Related Allowance 591us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember		 805us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember
Recorded Investment With No Related Allowance 62,611us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember		 58,820us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember
Unpaid Principal Balance With No Related Allowance 101,964us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember		 96,722us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember
Recorded Investment 69,123us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember		 76,452us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember
Unpaid Principal Balance 110,695us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember		 118,766us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember
Related Allowance 591us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember		 805us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialBuilderAndDeveloperMember
Other Commercial Construction [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 5,116us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember		 5,480us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember
Unpaid Principal Balance With Related Allowance 6,084us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember		 6,484us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember
Related Allowance 831us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember		 900us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember
Recorded Investment With No Related Allowance 19,657us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember		 20,738us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember
Unpaid Principal Balance With No Related Allowance 40,072us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember		 41,035us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember
Recorded Investment 24,773us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember		 26,218us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember
Unpaid Principal Balance 46,156us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember		 47,519us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember
Related Allowance 831us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember		 900us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherCommercialConstructionMember
Residential [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 86,691us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember		 88,970us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember
Unpaid Principal Balance With Related Allowance 104,630us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember		 107,343us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember
Related Allowance 4,405us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember		 4,296us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember
Recorded Investment With No Related Allowance 17,203us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember		 16,815us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember
Unpaid Principal Balance With No Related Allowance 27,886us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember		 26,750us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember
Recorded Investment 103,894us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember		 105,785us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember
Unpaid Principal Balance 132,516us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember		 134,093us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember
Related Allowance 4,405us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember		 4,296us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialRealEstateOtherMember
Residential Alt-A [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 97,984us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember		 101,137us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember
Unpaid Principal Balance With Related Allowance 110,835us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember		 114,565us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember
Related Allowance 11,000us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember		 11,000us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember
Recorded Investment With No Related Allowance 24,785us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember		 26,752us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember
Unpaid Principal Balance With No Related Allowance 43,635us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember		 46,964us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember
Recorded Investment 122,769us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember		 127,889us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember
Unpaid Principal Balance 154,470us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember		 161,529us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember
Related Allowance 11,000us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember		 11,000us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_ResidentialAltMember
Home Equity Lines and Loans [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 19,701us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember		 19,771us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember
Unpaid Principal Balance With Related Allowance 20,794us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember		 20,806us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember
Related Allowance 6,304us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember		 6,213us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember
Recorded Investment 19,701us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember		 19,771us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember
Unpaid Principal Balance 20,794us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember		 20,806us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember
Related Allowance 6,304us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember		 6,213us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_HomeEquityLinesAndLoansMember
Automobile [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 27,122us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember		 30,317us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember
Unpaid Principal Balance With Related Allowance 27,122us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember		 30,317us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember
Related Allowance 6,983us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember		 8,070us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember
Recorded Investment 27,122us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember		 30,317us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember
Unpaid Principal Balance 27,122us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember		 30,317us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember
Related Allowance 6,983us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember		 8,070us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_AutomobileLoanMember
Other [Member]    
Schedule Of Financial Receivables [Line Items]    
Recorded Investment With Related Allowance 18,814us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember		 18,973us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember
Unpaid Principal Balance With Related Allowance 18,814us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember		 18,973us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember
Related Allowance 5,297us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember		 5,459us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember
Recorded Investment 18,814us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember		 18,973us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember
Unpaid Principal Balance 18,814us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember		 18,973us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember
Related Allowance $ 5,297us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember		 $ 5,459us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= mtb_OtherLoansMember