Investments, Debt and Equity Securities [Abstract] Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Fair Value Disclosures [Abstract] Fair Value Fair Value Disclosures [Text Block] Receivables [Abstract] Schedule of allowance for loan and lease losses segregated by originated and acquired loan and lease portfolios and by portfolio segment Financing Receivable, Allowance for Credit Loss [Table Text Block] Schedule of allowance for loan and lease losses based on impairment methodology Schedule Of The Allowance For Loan And Lease Losses Based On Impairment Methodology [Table Text Block] Tabular disclosure of activity in the allowance for loan and lease losses based on impairment methodology. Schedule of recorded investment in loans and leases based on impairment methodology Impaired Financing Receivables [Table Text Block] Schedule of average recorded investment and interest income on impaired loans Schedule Of Recorded Investments In Impaired Loans Tabular disclosure of Impaired loans and allowance. Schedule of loans modified in troubled debt restructuring Schedule of Debtor Troubled Debt Restructuring, Current Period [Table Text Block] Schedule of credit quality indicators by class of commercial and industrial loans and commercial real estate loans Financing Receivable Credit Quality Indicators [Table Text Block] Schedule of credit quality indicators by class of residential real estate loans and consumer loans Schedule Of Credit Quality Indicators By Class Of Residential Real Estate And Consumer Loans [Table Text Block] Tabular disclosure of credit quality indicators by class of residential and consumer loans. Statement of Financial Position [Abstract] Available-for-sale securities, at amortized cost Debt Securities, Available-for-sale, Amortized Cost Held-to-maturity securities, at fair value Debt Securities, Held-to-maturity, Fair Value Equity securities, at amortized cost Equity Securities, FV-NI, Cost Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, authorized (in shares) Common Stock, Shares Authorized Common stock, issued (in shares) Common Stock, Shares, Issued Treasury stock, shares (in shares) Treasury Stock, Shares Revenue from Contract with Customer [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Commissions and Fees Commissions and Fees [Member] Commissions and Fees [Member] Installment Billing Installment Billing [Member] Installment Billing [Member] Refund of Commissions Refund Of Commissions [Member] Refund Of Commissions [Member] Contract Liabilities/Deferred Revenue Contract Liabilities and Deferred Revenue [Member] Contract Liabilities and Deferred Revenue [Member] Contingent Commissions Contingent Consideration [Member] Contingent Consideration [Member] Subtotal Insurance Revenues Total Insurance Revenues [Member] Total Insurance Revenues [Member] Trust and Asset Management Trust And Asset Management [Member] Trust And Asset Management [Member] Mutual Fund & Investment Income Mutual Fund And Investment Income [Member] Mutual Fund And Investment Income [Member] Subtotal Investment Service Income Subtotal Investment Service Income [Member] Subtotal Investment Service Income [Member] Service Charges on Deposit Accounts Service Charges On Deposit Accounts [Member] Service Charges On Deposit Accounts [Member] Card Services Income Card Services Income [Member] Card Services Income [Member] Other Other Non Interest Income [Member] Other Non Interest Income [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Noninterest Income (in-scope of ASC 606) Revenue from Contract with Customer, Excluding Assessed Tax Noninterest Income (out-of-scope of ASC 606) Noninterest Income, Other Operating Income, Not In Scope For Topic 606 Noninterest Income, Other Operating Income, Not In Scope For Topic 606 Total Noninterest Income Noninterest Income Noninterest income (out-of-scope of ASC 606), gain on sale of fixed asset Noninterest Income Other Operating Income Not In Scope For Topic 606 Gain Loss On Fixed Assets Noninterest Income, Other Operating Income, Not In Scope For Topic 606, Gain (Loss) On Fixed Assets Loans and Leases Receivable Disclosure [Abstract] Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Commercial and industrial Commercial And Industrial Portfolio Segment [Member] Commercial And Industrial Portfolio Segment [Member] Commercial real estate Commercial Real Estate Portfolio Segment [Member] Residential real estate Residential Portfolio Segment [Member] Consumer and other Consumer And Other Portfolio Segment [Member] Consumer And Other Portfolio Segment [Member] Leases Finance Leases Portfolio Segment [Member] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Originated Loans and Leases Loans Receivable [Member] Acquired Loans and Leases Acquired Loans and Leases [Member] An amount of money or property, or a portion thereof, leant to a borrower (debtor) in exchange for a promise to repay the amount borrowed plus interest at a date certain in the future. Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Agriculture Agriculture Loans [Member] Agriculture Loans [Member] Construction Construction Loans [Member] Consumer Other Other Financing Receivable [Member] Other Financing Receivable [Member] Home equity Home Equity Loan [Member] Mortgages Residential Mortgage [Member] Indirect Indirect Loans [Member] Indirect Loans [Member] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Domain] Financial Asset, Period Past Due [Domain] 30-89 days 30 - 89 Days [Member] Financing receivables that are more than 30 days past due but fewer than 90 days past due. 90 days or more Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Past due Financing Receivable, Past Due Current Loans Financing Receivable, Not Past Due Total Loans and Leases Receivable, Gross 90 days and accruing Financing Receivable, 90 Days or More Past Due, Still Accruing Nonaccrual Financing Receivable, Nonaccrual Less: unearned income and deferred costs and fees, Past due Loans and Leases Receivable, Deferred Income Less: unearned income and deferred costs and fees, Current Loans Loans And Leases Receivable, Current, Deferred Income Loans And Leases Receivable, Current, Deferred Income Less: unearned income and deferred costs and fees, 90 days and accruing Loans And Leases Receivable, Unearned Income and Deferred Fees, 90 Days and Accruing Loans And Leases Receivable, Unearned Income and Deferred Fees, 90 Days and Accruing Less: unearned income and deferred costs and fees, Nonaccrual Loans And Leases Receivable, Unearned Income and Deferred Fees, Nonaccrual Status Loans And Leases Receivable, Unearned Income and Deferred Fees, Nonaccrual Status Total loans and leases, net of unearned income and deferred costs and fees Loans and Leases Receivable, Net of Deferred Income Total originated loans and leases, net of unearned income and deferred costs and fees, Current Loans Loans And Leases Receivable, Current, Net Of Deferred Income Loans And Leases Receivable, Current, Net Of Deferred Income Earnings Per Share [Abstract] Antidilutive securities excluded from computation of earning per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Leases [Abstract] Schedule of operating lease amounts included in consolidated statement of condition and other information related to operating leases Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee [Table Text Block] Schedule of components of operating lease expense Lease, Cost [Table Text Block] Schedule of future minimum lease payments Lessee, Operating Lease, Liability, Maturity [Table Text Block] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Obligations of U.S. Government sponsored entities US Government-sponsored Enterprises Debt Securities [Member] Obligations of U.S. states and political subdivisions US States and Political Subdivisions Debt Securities [Member] U.S. Government agencies US Government Agencies Debt Securities [Member] U.S. Government sponsored entities Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] U.S. corporate debt securities Debt Security, Corporate, US [Member] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Available-for-sale securities Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] Fair Value, Less than 12 Months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Unrealized Losses, Less than 12 Months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Fair Value, 12 Months or Longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Unrealized Losses, 12 Months or Longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Fair Value Debt Securities, Available-for-sale, Unrealized Loss Position Unrealized Losses Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Held-to-maturity debt securities Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position [Abstract] Fair Value, Less than 12 Months Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value Unrealized Losses, Less than 12 Months Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Fair Value, 12 Months or Longer Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value Unrealized Losses, 12 Months or Longer Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Fair Value Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value Unrealized Losses Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss U.S. Treasuries US Treasury Securities [Member] Non-U.S. Government agencies or sponsored entities Mortgage-backed Securities, Issued by Private Enterprises [Member] Amortized Cost Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Fair Value Debt Securities, Available-for-sale Earnings Per Share Earnings Per Share [Text Block] Loans and Leases Loans, Notes, Trade and Other Receivables, Excluding Allowance for Credit Losses [Text Block] Summary of financial assets and financial liabilities measured at fair value on recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of assets measured at fair value on nonrecurring basis Fair Value Measurements, Nonrecurring [Table Text Block] Schedule of carrying amount and estimated fair value of financial instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule of Federal Home Loan Bank Advances, by Branch of FHLB Bank [Table] Schedule of Federal Home Loan Bank Advances, by Branch of FHLB Bank [Table] Federal Home Loan Bank Branch [Axis] Federal Home Loan Bank Branch [Axis] Federal Home Loan Bank Branch [Domain] Federal Home Loan Bank Branch [Domain] Federal Home Loan Bank New York (FHLBNY) Federal Home Loan Bank of New York [Member] Federal Home Loan Bank Pittsburgh (FHLBPITT) Federal Home Loan Bank of Pittsburgh [Member] Atlantic Central Bankers Bank (ACBB) Federal Home Loan Bank of Atlanta [Member] Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] Realized gains on available-for-sale debt securities Debt Securities, Available-for-sale, Realized Gain Realized losses on available-for-sale debt securities Debt Securities, Available-for-sale, Realized Loss Realized gains on equity securities, net Equity Securities, FV-NI, Realized Gain Realized losses on equity securities, net Equity Securities, FV-NI, Realized Loss Holdings of FHLBNY, FHLBPITT and ACBB stock, amount of advances Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances Schedule of basic and diluted earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Retirement Benefits [Abstract] Amortization of amounts previously recognized in accumulated other comprehensive income (loss) Amortization Of Amounts Previously Recognized In Accumulated Other Comprehensive Income Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans. Contribution to pension plan Defined Contribution Plan, Employer Discretionary Contribution Amount Other Income and Expenses [Abstract] Other Income and Operating Expense Other Operating Income and Expense [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Ownership [Axis] Ownership [Axis] Ownership [Domain] Ownership [Domain] Tompkins Insurance Agencies Inc Tompkins Insurance Agencies Inc [Member] Tompkins Insurance Agencies Inc [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Tompkins, Cayuga, Cortland and Schuyler Counties, New York Tompkins, Cayuga, Cortland and Schuyler Counties, New York [Member] Tompkins, Cayuga, Cortland and Schuyler Counties, New York [Member] Wyoming, Livingston, Genessee, Orleans and Monroe, New York Wyoming, Livingston, Genessee, Orleans and Monroe, New York [Member] Wyoming, Livingston, Genessee, Orleans and Monroe, New York [Member] Putnam Country, Dutchess Country and Westchester, New York Putnam Country, Dutchess Country and Westchester, New York [Member] Putnam Country, Dutchess Country and Westchester, New York [Member] Berks, Montgomery, Philadelphia, Deleware and Schuylkill, Pennsylvania Berks, Montgomery, Philadelphia, Deleware and Schuylkill, Pennsylvania [Member] Berks, Montgomery, Philadelphia, Deleware and Schuylkill, Pennsylvania [Member] Western New York Western New York [Member] Western New York [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of reportable segments Number of Reportable Segments Nature of operations, number of subsidiary banks Nature Of Operations, Number Of Subsidiary Banks Nature of Operations, Number of Subsidiary Banks Nature of operations, number of banking offices Nature Of Operations, Number Of Banking Offices Nature Of Operations, Number of Banking Offices Noncontrolling interest, ownership percentage by parent Noncontrolling Interest, Ownership Percentage by Parent Number of offices Nature Of Operations, Number of Offices Nature Of Operations, Number of Offices Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-maturity [Table] Financial Instruments [Domain] Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Amortized Cost Debt Securities, Held-to-maturity, Amortized Cost, before Other-than-temporary Impairment Gross Unrealized Gains Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain Gross Unrealized Losses Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss Fair Value Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Commercial and Industrial Commercial Real Estate Total Acquired Loans Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Pass Pass [Member] Special Mention Special Mention [Member] Substandard Substandard [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Loans and Leases, gross Loans And Leases, Gross Carrying Amount Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements. Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Remaining lease term Lease, Remaining Lease Term Lease, Remaining Lease Term Renewal term Lessee, Lease, Renewal Term Lessee, Lease, Renewal Term Termination period Lessee, Lease, Termination Period Lessee, Lease, Termination Period Operating lease commitments, 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating lease commitments, 2020 Operating Leases, Future Minimum Payments, Due in Two Years Operating lease commitments, 2021 Operating Leases, Future Minimum Payments, Due in Three Years Operating lease commitments, 2022 Operating Leases, Future Minimum Payments, Due in Four Years Operating lease commitments, 2023 Operating Leases, Future Minimum Payments, Due in Five Years Operating lease commitments, thereafter Operating Leases, Future Minimum Payments, Due Thereafter Operating lease renewal term Lessee, Operating Lease, Renewal Term ASSETS Assets [Abstract] Cash and noninterest bearing balances due from banks Cash and Due from Banks Interest bearing balances due from banks Interest-bearing Deposits in Banks and Other Financial Institutions Cash and Cash Equivalents Cash and Cash Equivalents, at Carrying Value Available-for-sale securities, at fair value (amortized cost of $1,140,086 at September 30, 2019 and $1,363,902 at December 31, 2018) Held-to-maturity securities, at amortized cost (fair value of $142,583 at September 30, 2019 and $139,377 at December 31, 2018) Debt Securities, Held-to-maturity Equity securities, at fair value (amortized cost $1,000 at September 30, 2019 and $1,000 at December 31, 2018) Equity Securities, FV-NI Originated loans and leases, net of unearned income and deferred costs and fees Originated Loans And Leases, Net Of Unearned Income And Deferred Costs And Fees Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements. Acquired loans Acquired Loans And Leases, Non-covered Refers to loans and leases receivable gross carrying amount not covered as of balance sheet date. Less: Allowance for loan and lease losses Loans and Leases Receivable, Allowance Net Loans and Leases Loans and Leases Receivable, Net Reported Amount, Covered and Not Covered Federal Home Loan Bank and other stock Federal Home Loan Bank Stock and Federal Reserve Bank Stock Bank premises and equipment, net Property, Plant and Equipment, Net Corporate owned life insurance Bank Owned Life Insurance Goodwill Goodwill Other intangible assets, net Intangible Assets, Net (Excluding Goodwill) Accrued interest and other assets Interest Receivable and Other Assets Total Assets Assets LIABILITIES Liabilities [Abstract] Deposits: Deposits [Abstract] Interest bearing: Interest-bearing Deposit Liabilities [Abstract] Checking, savings and money market Checking, Savings And Money Market Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs). Time Time Deposits Noninterest bearing Noninterest-bearing Deposit Liabilities Total Deposits Deposits Federal funds purchased and securities sold under agreements to repurchase Federal Funds Purchased and Securities Sold under Agreements to Repurchase Other borrowings Other Borrowings Trust preferred debentures Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount Other liabilities Other Liabilities Total Liabilities Liabilities EQUITY Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Tompkins Financial Corporation shareholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Common Stock - par value $.10 per share: Authorized 25,000,000 shares; Issued: 15,011,660 at September 30, 2019; and 15,348,287 at December 31, 2018 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Treasury stock, at cost – 121,880 shares at September 30, 2019, and 122,227 shares at December 31, 2018 Treasury Stock, Value Total Tompkins Financial Corporation Shareholders’ Equity Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total Liabilities and Equity Liabilities and Equity Residential Real Estate Consumer and Other Finance Leases Individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Loans acquired with deteriorated credit quality Loans acquired with deteriorated credit quality Refers to deteriorated credit quality of acquired receivables. Collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Stockholders' Equity Note [Abstract] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-01 Accounting Standards Update 2016-01 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Available-for- Sale Securities AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] Employee Benefit Plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Other Comprehensive (Loss) Income AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Balances at Beginning Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive (loss) income Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Cumulative effect of new accounting principle Cumulative Effect of New Accounting Principle in Period of Adoption Balances at Ending Organization, Consolidation and Presentation of Financial Statements [Abstract] Business Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] ROU assets Operating Lease, Right-of-Use Asset Current lease liabilities Operating Lease, Liability, Current Non-current lease liabilities Operating Lease, Liability, Noncurrent Total lease liabilities Operating Lease, Liability Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Carrying Amount Reported Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial Assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Securities - held to maturity FHLB and other stock Accrued interest receivable Interest Receivable Loans/leases, net Loans Receivable, Fair Value Disclosure Financial Liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Time deposits Other deposits Other Deposits, Fair Value Disclosure Represents fair value of other deposits. Fed funds purchased and securities sold under agreements to repurchase Other borrowings Accrued interest payable Interest Payable Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Treasury Stock Treasury Stock [Member] Non- controlling Interests Noncontrolling Interest [Member] Accounting Standards Update 2014-09 Accounting Standards Update 2014-09 [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Net income attributable to noncontrolling interests and Tompkins Financial Corporation Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Other comprehensive income (loss) Subtotal comprehensive income attributable to noncontrolling interests and Tompkins Financial Corporation Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Cash dividends Dividends, Common Stock, Cash Net exercise of stock options Stock Issued, Value, Stock Options Exercised, Net of Tax Benefit (Expense) Common stock repurchased and returned to unissued status Stock Repurchased During Period, Value Stock-based compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition Shares issued for employee stock ownership plan Stock Issued During Period, Value, Employee Stock Ownership Plan Directors deferred compensation plan Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture Restricted stock activity Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Partial repurchase of noncontrolling interest Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Segment and Related Information Segment Reporting Disclosure [Text Block] Allowance for Loan and Lease Losses Allowance for Credit Losses [Text Block] Accounting Policies [Abstract] Accounting Standards Updates New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] VIST Financial Corp. (VIST Financial) VIST Financial Corp. ("VIST Financial") [Member] Refers to VIST financial corp. Acquired Credit Impaired Loans Acquired Credit Impaired Loans [Member] Refers to acquired credit impaired loans. Acquired Non-Credit Impaired Loans Acquired Non Credit Impaired Loans [Member] Refers to acquired non credit impaired loans. Outstanding principal balance Impaired Financing Receivable, Unpaid Principal Balance Carrying amount Impaired Financing Receivable, Recorded Investment Guarantees [Abstract] Obligations to extend credit for loan commitments Guarantor Obligations, Maximum Exposure, Undiscounted Basic Earnings Per Share, Basic [Abstract] Net income available to common shareholders Net Income (Loss) Attributable to Parent Less: income attributable to unvested stock-based compensation awards Income Allocated To Unvested Restricted Stock Awards This element represents the income allocated to unvested restricted stock awards. Net earnings allocated to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Weighted average shares outstanding, including unvested stock-based compensation awards (in shares) Weighted Average Number of Shares Issued, Basic Less: unvested stock-based compensation awards (in shares) Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights Weighted average shares outstanding - Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted Earnings Per Share, Diluted [Abstract] Net earnings allocated to common shareholders Net Income (Loss) Available to Common Stockholders, Diluted Weighted average shares outstanding - Basic (in shares) Plus: Incremental shares from assumed conversion of stock-based compensation awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted average shares outstanding - Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Basic EPS (in dollars per share) Earnings Per Share, Basic Diluted EPS (in dollars per share) Earnings Per Share, Diluted Cover page. Document Type Document Type Document Quarterly Report Document Quarterly Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Central Index Key Entity Central Index Key Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Document Fiscal Period Focus Document Fiscal Period Focus Document Fiscal Year Focus Document Fiscal Year Focus Schedule of available-for-sale securities Debt Securities, Available-for-sale [Table Text Block] Schedule of held-to-maturity securities Debt Securities, Held-to-maturity [Table Text Block] Schedule of available-for-sale securities with unrealized losses Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block] Schedule held-to-maturity securities with unrealized losses Schedule Held-to-maturity Securities With Unrealized Losses [Table Text Block] Tabular disclosure of fair value of investments in debt and equity securities in an unrealized loss position categorized as held-to-maturity. Schedule of amortized cost and estimated fair value of debt securities by contractual maturity Investments Classified by Contractual Maturity Date [Table Text Block] Net unrealized gain/loss AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Including Noncontrolling Interest [Member] Amortization of net retirement plan actuarial gain/loss Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] Amortization of net retirement plan prior service cost Accumulated Defined Benefit Plans Adjustment, Net Prior Service Including Portion Attributable to Noncontrolling Interest [Member] Employee benefit plans Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member] Before-Tax Amount Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax [Abstract] Change in net unrealized gain/loss during the period Other Comprehensive Income (Loss), before Reclassifications, before Tax Reclassification adjustment for net realized gain on sale of available-for-sale securities included in net income Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Net unrealized gains/losses / Other comprehensive income (loss) Other Comprehensive Income (Loss), before Tax Tax (Expense) Benefit Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax [Abstract] Change in net unrealized gain/loss during the period Other Comprehensive Income (Loss) before Reclassifications, Tax Reclassification adjustment for net realized gain on sale of available-for-sale securities included in net income Reclassification from AOCI, Current Period, Tax Net unrealized gains/losses / Other comprehensive income (loss) Other Comprehensive Income (Loss), Tax Net of Tax Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract] Change in net unrealized gain/loss during the period Reclassification adjustment for net realized gain on sale of available-for-sale securities included in net income Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Average Recorded Investment, With no related allowance Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Interest Income Recognized, With no related allowance Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method Average Recorded Investment, With related allowance Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Interest Income Recognized, With related allowance Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Total Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Total Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Revenue, Initial Application Period Cumulative Effect Transition [Table] Revenue, Initial Application Period Cumulative Effect Transition [Table] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Difference between Revenue Guidance in Effect before and after Topic 606 Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Insurance Insurance [Member] Information pertaining to the company-identified Insurance segment. Wealth Management Wealth Management [Member] Information pertaining to the company-identified Wealth Management segment. Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Revenue, performance obligation, description of timing Revenue, Performance Obligation, Description of Timing Contract with customer, asset, net Contract with Customer, Asset, after Allowance for Credit Loss Contract with customer, liability Contract with Customer, Liability Amortized Cost Debt Securities, Held-to-maturity, Maturity, Amortized Cost, Net [Abstract] Due in one year or less Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Due after one year through five years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost Due after five years through ten years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost Total held-to-maturity debt securities Fair Value Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract] Due in one year or less Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Due after one year through five years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Due after five years through ten years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Total held-to-maturity debt securities Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Available-for-sale securities Debt Securities [Member] Mortgage-backed securities Collateralized Mortgage Backed Securities [Member] Amortized Cost Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract] Due in one year or less Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Due after one year through five years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost Due after five years through ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost Due after ten years Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost Fair Value Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract] Due in one year or less Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Due after one year through five years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Due after five years through ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Due after ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Total Revenue Recognition Revenue from Contract with Customer [Text Block] Schedule of loans and leases Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Schedule of outstanding principal and carrying amount of loans acquired Schedule Of Outstanding Principal And Carrying Amount Of Loans Acquired [Table Text Block] Tabular disclosure of outstanding principal and carrying amounts of acquired loans. Schedule of age analysis of past due loans, segregated by originated and acquired loan and lease portfolios and by class of loans Financing Receivable, Past Due [Table Text Block] Statement of Cash Flows [Abstract] OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net income attributable to Tompkins Financial Corporation Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Provision for loan and lease losses Provision for Loan and Lease Losses Depreciation and amortization of premises, equipment, and software Other Depreciation and Amortization Amortization of intangible assets Amortization of Intangible Assets Earnings from corporate owned life insurance Bank Owned Life Insurance Income Net amortization on securities Accretion (Amortization) of Discounts and Premiums, Investments Amortization/accretion related to purchase accounting Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion Net gain on securities transactions Marketable Securities, Realized Gain (Loss), Excluding Other-than-temporary Impairment Loss Net gain on sale of loans originated for sale Gain (Loss) on Sales of Loans, Net Proceeds from sale of loans originated for sale Proceeds from Sale of Loans Held-for-sale Loans originated for sale Payments for Origination and Purchases of Loans Held-for-sale Net gain on sale of bank premises and equipment Gain (Loss) on Disposition of Property Plant Equipment Net excess tax benefit from stock based compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Stock-based compensation expense Share-based Payment Arrangement, Noncash Expense Increase in accrued interest receivable Increase (Decrease) in Interest Payable, Net (Decrease) increase in accrued interest payable Increase (Decrease) in Accrued Investment Income Receivable Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Operating Activities INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Proceeds from maturities, calls and principal paydowns of available-for-sale securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Proceeds from sales of available-for-sale securities Proceeds from Sale of Debt Securities, Available-for-sale Proceeds from maturities, calls and principal paydowns of held-to-maturity securities Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities Purchases of available-for-sale securities Payments to Acquire Debt Securities, Available-for-sale Purchases of held-to-maturity securities Payments to Acquire Held-to-maturity Securities Net increase in loans Payments for (Proceeds from) Loans and Leases Net decrease in Federal Home Loan Bank stock Payments for (Proceeds from) Federal Home Loan Bank Stock Proceeds from sale of bank premises and equipment Proceeds from Sale of Property, Plant, and Equipment Purchases of bank premises, equipment and software Payments to Acquire Property, Plant, and Equipment Net cash used in acquisition Payments for (Proceeds from) Previous Acquisition Other, net Payments for (Proceeds from) Other Investing Activities Net Cash Provided by (Used in) Investing Activities Net Cash Provided by (Used in) Investing Activities FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Net increase in demand, money market, and savings deposits Increase (Decrease) in Deposits Net increase (decrease) in time deposits Increase (Decrease) in Time Deposits Net decrease in Federal funds purchased and securities sold under agreements to repurchase Increase (Decrease) in Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Net Increase in other borrowings Proceeds from Issuance of Debt Repayment of other borrowings Repayments of Debt Cash dividends Payments of Ordinary Dividends, Common Stock Repurchase of common stock Payments for Repurchase of Common Stock Shares issued for employee stock ownership plan Proceeds from Stock Plans Net shares issued related to restricted stock awards Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Excluding Stock Options, Net Of Tax Withholdings Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Excluding Stock Options, Net Of Tax Withholdings Net proceeds from exercise of stock options Proceeds from Stock Options Exercised Net Cash (Used in) Provided by Financing Activities Net Cash Provided by (Used in) Financing Activities Net Increase in Cash and Cash Equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents at beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Total Cash and Cash Equivalents at End of Period Supplemental Information: Supplemental Cash Flow Information [Abstract] Cash paid during the year for - Interest Interest Paid, Excluding Capitalized Interest, Operating Activities Cash paid during the year for - Taxes Income Taxes Paid, Net Transfer of loans to other real estate owned Transfer Of Loans To Other Real Estate Owned Value of loans transferred to other real estate owned in noncash transactions during the reporting period. Operating lease cost Operating Lease, Cost Variable lease cost Variable Lease, Cost Short-term lease cost Short-term Lease, Cost Sublease income Sublease Income Total lease cost Lease, Cost Allowance for originated loans and leases Allowance for Loan and Lease Losses [Roll Forward] Allowance for Loan and Lease Losses [Roll Forward] Beginning balance Charge-offs Allowance for Loan and Lease Losses, Write-offs Recoveries Allowance for Loan and Lease Loss, Recovery of Bad Debts Provision (credit) Ending Balance Income Statement [Abstract] INTEREST AND DIVIDEND INCOME Interest and Dividend Income, Operating [Abstract] Loans Interest and Fee Income, Other Loans Due from banks Interest Income, Deposits with Financial Institutions Available-for-sale securities Interest Income, Debt Securities, Available-for-sale, Operating Held-to-maturity securities Interest Income, Debt Securities, Held-to-maturity Federal Home Loan Bank and other stock Income Federal Home Loan Bank And Other Stock Refers to income recognized during the period from federal home loan bank and Other stock Total Interest and Dividend Income Interest and Dividend Income, Operating INTEREST EXPENSE Interest Expense [Abstract] Time certificates of deposits of $250,000 or more Interest Expense, Time Deposits, $250,000 or More Interest Expense, Time Deposits, $250,000 or More Other deposits Interest Expense, Other Domestic Deposits Federal funds purchased and securities sold under agreements to repurchase Interest Expense, Federal Funds Purchased and Securities Sold under Agreements to Repurchase Trust preferred debentures Interest Expense, Trust Preferred Securities Other borrowings Interest Expense, Borrowings Total Interest Expense Interest Expense Net Interest Income Interest Income (Expense), Net Less: Provision for loan and lease losses Net Interest Income After Provision for Loan and Lease Losses Interest Income (Expense), after Provision for Loan Loss NONINTEREST INCOME Noninterest Income [Abstract] Insurance commissions and fees Insurance Commissions and Fees Investment services income Investment services income Fees from trust, investment and asset management and other wealth advisory services. A portion of these fees is based on the market value of client assets managed, advised, administered or held in custody. The remaining portion of these fees is based on the specific service provided or may be fixed fees. Service charges on deposit accounts Fees and Commissions, Depositor Accounts1 Fees and Commissions, Depositor Accounts1 Card services income Fees and Commissions, Credit Cards 1 Fees and Commissions, Credit Cards 1 Other income Noninterest Income, Other Operating Income Net gain on securities transactions Debt Securities, Available-for-sale, Realized Gain (Loss) NONINTEREST EXPENSE Noninterest Expense [Abstract] Salaries and wages Salary and Wage, NonOfficer, Excluding Cost of Good and Service Sold Other employee benefits Other Postretirement Benefits Cost (Reversal of Cost) Net occupancy expense of premises Occupancy, Net Furniture and fixture expense Equipment Expense Other operating expense Other Noninterest Expense Total Noninterest Expenses Noninterest Expense Income Before Income Tax Expense Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income Tax Expense Income Tax Expense (Benefit) Net Income Attributable to Noncontrolling Interests and Tompkins Financial Corporation Less: Net Income Attributable to Noncontrolling Interests Net Income (Loss) Attributable to Noncontrolling Interest Net Income Attributable to Tompkins Financial Corporation Basic Earnings Per Share (in dollars per share) Diluted Earnings Per Share (in dollars per share) Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Leasing Lessee, Operating Leases [Text Block] Three Months 2019 Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five 2024 and subsequent years Lessee, Operating Lease, Liability, Payments, Due after Year Five Total lease payments Lessee, Operating Lease, Liability, Payments, Due Less: Interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Present value of lease liabilities Individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Ending balance Performing Performing Financial Instruments [Member] Nonperforming Nonperforming Financial Instruments [Member] Loans and Leases, gross LoansAndLeasesReceivableGrossCarryingAmount2 Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements. Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Intercompany Intersegment Eliminations [Member] Banking Banking [Member] Interest income Interest expense Noninterest income Noninterest expense Income tax expense Less: Net income attributable to noncontrolling interests Depreciation and amortization Assets Other intangibles, net Net loans and leases Deposits Total Equity Basis of Presentation Basis of Accounting [Text Block] Originated Acquired Total loans and leases Less: unearned income and deferred costs and fees Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Table] Commercial and industrial, real estate other Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Troubled Debt Restructuring [Line Items] Number of Loans Financing Receivable, Modifications, Number of Contracts Pre-Modification Outstanding Recorded Investment Financing Receivable, Troubled Debt Restructuring, Premodification Post-Modification Outstanding Recorded Investment Financing Receivable, Troubled Debt Restructuring, Postmodification Number of Loans Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Post-Modification Outstanding Recorded Investment Financing Receivable, Troubled Debt Restructuring, Subsequent Default Schedule of disaggregation of noninterest income, segregated by revenue streams in-scope and out-of-scope of ASC 606 Disaggregation of Revenue [Table Text Block] Statement of Comprehensive Income [Abstract] Net income attributable to noncontrolling interests and Tompkins Financial Corporation Other comprehensive income (loss), net of tax: Other comprehensive income, net of tax: Available-for-sale securities: Change in net unrealized gain/(loss) during the period Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Reclassification adjustment for net realized gain on sale of available-for-sale securities included in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Employee benefit plans: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract] Amortization of net retirement plan actuarial loss Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Amortization of net retirement plan prior service cost Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax Less: Net income attributable to noncontrolling interests Total comprehensive income attributable to Tompkins Financial Corporation Comprehensive Income (Loss), Net of Tax, Attributable to Parent Schedule of other income and operating expense Schedule of Other Nonoperating Income (Expense) [Table Text Block] Operating cash flows from operating leases Operating Lease, Payments Weighted-average remaining lease term on operating leases Operating Lease, Weighted Average Remaining Lease Term Weighted-average discount rates on operating leases Operating Lease, Weighted Average Discount Rate, Percent ROU assets obtained in exchange for lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Number of wholly owned subsidiaries Nature Of Operations, Number Of Wholly Owned Subsidiaries Nature Of Operations, Number Of Wholly Owned Subsidiaries Employee Benefit Plan Compensation and Employee Benefit Plans [Text Block] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Non-Recurring Fair Value, Nonrecurring [Member] Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Impaired loans Impaired Loans Refers to fair value amount of collateral dependent impaired loans as of balance sheet date. Gain (losses) from fair value changes on impaired loans Gain (Loss) on Impaired Loans Refers to gain loss on collateral dependent impaired loans incurred during the period. Other real estate owned Other Real Estate Owned Refers to fair value amount of other real estate owned as of balance sheet date. Gain (losses) from fair value changes on other real estate owned Gain (Loss) On Other Real Estate Owned Refers to gain loss on other real estate owned incurred during the period. Financial Guarantees Guarantees [Text Block] Recorded Investment, With no related allowance Impaired Financing Receivable, with No Related Allowance, Recorded Investment Unpaid Principal Balance, With no related allowance Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Recorded Investment, With related allowance Impaired Financing Receivable, with Related Allowance, Recorded Investment Unpaid Principal Balance, With related allowance Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Related Allowance Impaired Financing Receivable, Related Allowance Recorded Investment Unpaid Principal Balance Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Amount Reclassified from Accumulated Other Comprehensive (Loss) Income Reclassification out of Accumulated Other Comprehensive Income [Member] Available-for-sale securities Net retirement plan actuarial loss Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] Net retirement plan prior service cost Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Employee benefit plans Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] Net gain on securities transactions Tax (expense) benefit Net of tax Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Other operating expense Net of tax Schedule of activity in accumulated other comprehensive income (loss) and amounts reclassified out of each component of accumulated other comprehensive (loss) income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of reclassifications out of accumulated other comprehensive income (loss) Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Cash dividends (in dollars per share) Common Stock, Dividends, Per Share, Declared Net exercise of stock options (in shares) Net Exercise Of Stock Options And Related Tax Benefit, Shares The number of shares issued upon the exercise of stock options during the period, net of tax benefit. Common stock repurchased and returned to unissued status (in shares) Stock Repurchased During Period, Shares Shares issued for employee stock ownership plan (in shares) Stock Issued During Period, Shares, Employee Stock Ownership Plan Directors deferred compensation plan (in shares) Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Restricted stock activity (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Schedule of segment and related information Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of components of net periodic benefit cost Schedule of Net Benefit Costs [Table Text Block] Reporting threshold for other income and operating expenses (percent, greater than) Reporting Threshold For Other Income And Operating Expenses The percentage of aggregate total noninterest income and total noninterest expense above which items of other income and operating expense are presented. Noninterest Income Other service charges Other Service Charges The noninterest income derived from the other service charges. Increase in cash surrender value of corporate owned life insurance Net gain (loss) on sale of fixed assets Gain (Loss) on Disposition of Assets Other income Noninterest Income, Other Total other income Noninterest Expenses Marketing expense Marketing Expense Professional fees Professional Fees Legal fees Legal Fees Software, license, and maintenance Software, License, And Maintenance Expense Represents software licensing and maintenance expenses. Cardholder expense Cardholder expense Amount of expense associated with cardholder. FDIC insurance Federal Deposit Insurance Corporation Premium Expense Other expenses Other expenses Represents other expenses classified under noninterest expenses. Total other operating expense Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension Benefits Pension Plan [Member] Life and Health Other Postretirement Benefits Plan [Member] SERP Benefits Supplemental Employee Retirement Plan [Member] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Components of net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of net retirement plan actuarial loss Defined Benefit Plan, Amortization of Gain (Loss) Amortization of net retirement plan prior service (credit) cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Net periodic benefit (income) cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) New Adopted Accounting Standards and Accounting Standards Pending Adoption New Accounting Pronouncements, Policy [Policy Text Block] Recurring Fair Value, Recurring [Member] Fair Value Equity securities Equity Securities [Member] Fair Value Hierarchy and NAV [Domain] Available-for-sale securities Equity securities, at fair value