Other Income and Expenses [Abstract] Other Noninterest Income and Expense Other Income and Other Expense Disclosure [Text Block] Loans and Leases Receivable Disclosure [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Combination, Acquiree [Domain] Business Acquisition, Acquiree [Domain] VIST VIST Financial Corp. ("VIST Financial") [Member] Refers to VIST financial corp. Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] 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. Total Acquired Loans 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. Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Outstanding principal balance Impaired Financing Receivable, Unpaid Principal Balance Carrying amount Impaired Financing Receivable, Recorded Investment Receivables [Abstract] Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Originated Loans and Leases Loans Receivable [Member] Acquired Loans and Leases 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] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Domain] Class of Financing Receivable, Type [Domain] Other Other Financing Receivable [Member] Other Financing Receivable [Member] Home equity Home Equity Loan [Member] Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] 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 Banking and Thrift [Abstract] Time Deposits [Table] Time Deposits [Table] Time Deposit Liability [Axis] Time Deposit Liability [Axis] Information by type amount of time deposit liability. Time Deposit Liability [Domain] Time Deposit Liability [Domain] Less than $250,000 Less Than $250,000 [Member] Deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. $250,000 and over Two Hundred And Fifty Thousand Dollars And Over [Member] Deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time Deposits [Line Items] Time Deposits [Line Items] Maturity Maturity: Three months or less Three Months Or Less The value of time deposits maturing within three months. Over three through six months Over Three Through Six Months Amount of time deposits maturing in over three months through six months. Over six through twelve months Over Six Through Twelve Months Amount of time deposits maturing in over six months through twelve months. Total due in 2019 Time Deposit Maturities, Next Twelve Months 2020 Time Deposit Maturities, Year Two 2021 Time Deposit Maturities, Year Three 2022 Time Deposit Maturities, Year Four 2023 Time Deposit Maturities, Year Five 2024 Time Deposit Maturities, after Year Five Total Time Deposits Stockholders' Equity Note [Abstract] 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 Income Reclassification out of Accumulated Other Comprehensive Income [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Unrealized gains and losses on available-for-sale securities Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Net retirement plan actuarial gain Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] Net retirement plan prior service credit Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Employee Benefit Plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Net (loss) gain on securities transactions Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Tax benefit Income Tax Expense (Benefit) Net of tax Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Other operating expense Other Noninterest Expense Net income attributable to Tompkins Financial Corporation Net Income (Loss) Attributable to Parent Property, Plant and Equipment [Abstract] Schedule of premise and equipment Property, Plant and Equipment [Table Text Block] Schedule of depreciation and amortization Schedule Of Depreciation And Amortization Tabular disclosure of depreciation and amortization related to premises and equipment. Schedule of future minimum lease payments Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Consumer and other Consumer And Other Portfolio Segment [Member] Consumer And Other Portfolio Segment [Member] Leases Finance Leases Portfolio Segment [Member] Agriculture Agriculture Loans [Member] Agriculture Loans [Member] Construction Construction Loans [Member] Indirect Indirect Loans [Member] Indirect Loans [Member] Total loans and leases Loans and Leases Receivable, Gross Less: unearned income and deferred costs and fees Loans and Leases Receivable, Deferred Income Total originated loans and leases, net of unearned income and deferred costs and fees Loans and Leases Receivable, Net of Deferred Income Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Loan commitments Commitments to Extend Credit [Member] Standby letters of credit Standby Letters of Credit [Member] Undisbursed portion of lines of credit Line of Credit [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Obligations to extend credit for loan commitments Guarantor Obligations, Maximum Exposure, Undiscounted Rate lock agreements Rate Lock Agreements Value of rate-lock agreements associated with mortgage loans to be sold in the secondary market. Agreements to sell mortgages on a loan-by-loan basis Agreements To Sell Mortgages On A Loan-by-loan Basis Value of agreements to sell loans and mortgages in the secondary market, entered into to offset risk of rate-lock agreements. 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 Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Time deposits, greater than $250,000 Time Greater Than Two Hundred Fifty Thousand Dollars The aggregate amount of domestic time deposit liabilities in denominations of $250,000 or more. Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Mortgages Residential Mortgage [Member] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Domain] Financing Receivables, 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 Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Financing Receivable, Recorded Investment, Past Due [Line Items] Financing Receivable, Recorded Investment, Past Due [Line Items] Past due Financing Receivable, Recorded Investment, Past Due Current Loans Financing Receivable, Recorded Investment, Current Total Loans 90 days and accruing Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing Nonaccrual Financing Receivable, Recorded Investment, Nonaccrual Status Less: unearned income and deferred costs and fees, current 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 originated loans and leases, net of unearned income and deferred costs and fees, current Loans And Leases Receivable, Current, Net Of Deferred Income Loans And Leases Receivable, Current, Net Of Deferred Income Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Ithaca, NY Tompkins, Cayuga, Cortland and Schuyler Counties, New York [Member] Tompkins, Cayuga, Cortland and Schuyler Counties, New York [Member] Genesee Valley Region Wyoming, Livingston, Genessee, Orleans and Monroe, New York [Member] Wyoming, Livingston, Genessee, Orleans and Monroe, New York [Member] Counties North of New York City Putnam Country, Dutchess Country and Westchester, New York [Member] Putnam Country, Dutchess Country and Westchester, New York [Member] Southeastern 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 business segments Number of Reportable Segments Number of subsidiary banks Nature Of Operations, Number Of Subsidiary Banks Nature of Operations, Number of Subsidiary Banks Number of banking offices Nature Of Operations, Number Of Banking Offices Nature Of Operations, Number of Banking Offices Nature of operations, number of offices Nature Of Operations, Number of Offices Nature Of Operations, Number of Offices Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] $35.71-37.50 Stock Options Tranche 1 [Member] Contracts conveying rights, but not obligations, to buy or sell a specific quantity of stock at a specified price during a specified period (an American option) or at a specified date (a European option). $37.51-41.00 Stock Options Tranche 2 [Member] Contracts conveying rights, but not obligations, to buy or sell a specific quantity of stock at a specified price during a specified period (an American option) or at a specified date (a European option). $41.01-50.00 Stock Options Tranche 3 [Member] Contracts conveying rights, but not obligations, to buy or sell a specific quantity of stock at a specified price during a specified period (an American option) or at a specified date (a European option). $50.01-76.90 Stock Options Tranche 4 [Member] Contracts conveying rights, but not obligations, to buy or sell a specific quantity of stock at a specified price during a specified period (an American option) or at a specified date (a European option). $76.91-86.18 Stock Options Tranche 5 [Member] Contracts conveying rights, but not obligations, to buy or sell a specific quantity of stock at a specified price during a specified period (an American option) or at a specified date (a European option). Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Range of exercise prices, lower range (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Range of exercise prices, upper range (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Outstanding (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Weighted average remaining contractual life (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted average exercise price (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Number exercisable (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted average exercise price (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Deposits Deposit Liabilities Disclosures [Text Block] Accounting Policies [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Accumulated Other Comprehensive (Loss) Income AOCI Attributable to Parent [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Insurance Business Segment Insurance Business Segment [Member] Insurance Business Segment [Member] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Contingent Consideration Contingent Consideration [Member] Contingent Consideration [Member] 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] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2014-09 Accounting Standards Update 2014-09 [Member] Accounting Standards Update 2016-01 Accounting Standards Update 2016-01 [Member] Accounting Standards Update 2018-02 Accounting Standards Update 2018-02 [Member] Accounting Standards Update 2018-02 [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Building Building [Member] Furniture, fixtures, and equipment Furniture and Fixtures [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Core deposit intangible Core Deposits [Member] Covenants Noncompete Noncompete Agreements [Member] Customer relationships Customer Relationships [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Reserve requirements for banking subsidiaries Reserve requirements for banking subsidiaries Reserve requirements for banking companies, under applicable banking regulations. Estimated useful (in years) Property, Plant and Equipment, Useful Life Amortization period for other intangible assets (in years) Finite-Lived Intangible Asset, Useful Life Investment in qualified affordable housing projects Amortization Method Qualified Affordable Housing Project Investments Retained earnings Retained Earnings (Accumulated Deficit) Noninterest income Noninterest Income Adoption of ASU 2016-01 Cumulative Effect of New Accounting Principle in Period of Adoption Reclassification due to the adoption of ASU No. 2018-02 Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings Schedule of Repurchase Agreement Counterparty [Table] Schedule of Repurchase Agreement Counterparty [Table] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Securities Sold Under Agreements to Repurchase Securities Sold under Agreements to Repurchase [Member] Federal Funds Purchased Federal Funds Purchased [Member] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Retail Repurchase Agreements Retail Repurchase Agreements [Member] Value of securities sold under retail repurchase agreements. Wholesale Repurchase Agreements Wholesale Repurchase Agreements [Member] Value of securities sold under wholesale repurchase agreements. Repurchase Agreement Counterparty [Line Items] Repurchase Agreement Counterparty [Line Items] Total outstanding at December 31 Securities Sold under Agreements to Repurchase Maximum month-end balance Maximum Month-end Balance The maximum month end balance of securities sold under repurchase agreements. Average balance during the year Average Balance During the Year The calculated average balance during the year. Weighted average rate at December 31 Weighted Average Rate at December 31 The calculated weighted average interest rate. Average interest rate paid during the year Average Interest Rate Paid During the Year The calculated average interest rate paid during the year. Allowance for Loan and Lease Losses Allowance for Credit Losses [Text Block] 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] Loans and leases 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. Retirement Benefits [Abstract] 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] DB Pension Plans Pension Plan [Member] Life and Healthcare Plan Other Postretirement Benefits Plan [Member] SERP Plan 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] Discount Rates Discount Rates Benefit Cost for Plan Year Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Benefit Obligation at End of Plan Year Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Expected long-term return on plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Rate of compensation increase RateOfCompensationIncreaseAbstract Benefit Cost for Plan Year Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Benefit Obligation at End of Plan Year Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase Future Benefit Payments Defined Benefit Plan, Expected Future Benefit Payment [Abstract] 2019 Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months 2020 Defined Benefit Plan, Expected Future Benefit Payment, Year Two 2021 Defined Benefit Plan, Expected Future Benefit Payment, Year Three 2022 Defined Benefit Plan, Expected Future Benefit Payment, Year Four 2023 Defined Benefit Plan, Expected Future Benefit Payment, Year Five 2024-2028 Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter Total Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year Schedule of segment and related information Schedule of Segment Reporting Information, by Segment [Table Text Block] Quarterly financial information Quarterly Financial Information [Table Text Block] Premises Building and Building Improvements [Member] Depreciation and amortization expense Depreciation, Depletion and Amortization, Nonproduction Schedule of changes in the projected benefit obligations Schedule of Changes in Projected Benefit Obligations [Table Text Block] Schedule of net periodic benefit cost and other comprehensive income Schedule of Net Benefit Costs [Table Text Block] Schedule of pre-tax amounts recognized as a component of accumulated other comprehensive income Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block] Schedule of pre-tax amounts expected to be recognized Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year [Table Text Block] Schedule of weighted-average assumptions Schedule of Assumptions Used [Table Text Block] Schedule of expected benefits to be paid in each of next five years Schedule of Expected Benefit Payments [Table Text Block] Schedule of weighted average asset allocation of plans Schedule of Allocation of Plan Assets [Table Text Block] Schedule of fair value measurement of pension plan Schedule of fair value measurement of pension plan The tabular disclosure for the fair value measurement of pension plan. Land Land [Member] Premise and equipment, gross Property, Plant and Equipment, Gross Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total Property, Plant and Equipment, Net Change in benefit obligation: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Benefit obligation at beginning of year Defined Benefit Plan, Benefit Obligation Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Plan participants’ contributions Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant Amendments Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment Curtailments Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment Actuarial loss (gain) Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Benefit obligation at end of year Change in plan assets: Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Fair value of plan assets at beginning of year Defined Benefit Plan, Plan Assets, Amount Actual return on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Plan participants’ contributions Defined Benefit Plan, Plan Assets, Contributions by Plan Participant Employer contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid Fair value of plan assets at end of year Unfunded status Defined Benefit Plan, Funded (Unfunded) Status of Plan Commitments and Contingent Liabilities Commitments and Contingencies Disclosure [Text Block] Debt Disclosure [Abstract] Line of Credit Facility [Table] Line of Credit Facility [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Subsidiaries Subsidiaries [Member] Lender Name [Axis] Lender Name [Axis] Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Maximum borrowing capacity, lines of credit Line of Credit Facility, Maximum Borrowing Capacity Long-term line of credit Long-term Line of Credit Unused borrowing capacity on established lines with FHLB Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds Unencumbered residential and commercial real estate loan Unencumbered Residential And Commercial Real Estate Loan Amount refers to unencumbered residential and commercial real estate loan. Overnight FHLB advances Federal Home Loan Bank Advances, Overnight Federal Home Loan Bank Advances, Overnight Term advances from FHLB Long-term Federal Home Loan Bank Advances Weighted average interest rate (percent) Federal Home Loan Bank, Advances, Activity for Year, Average Interest Rate at Period End Term advances mature within one year Federal Home Loan Bank, Advances, Maturities Summary, Due in Next Twelve Months Term advances maturing after one year Term Advances Maturing After One Year Amount of federal home loan bank advances maturing after the next fiscal year following the latest fiscal year. Term advances mature in 2019 Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Two Term advances mature in 2020 Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Three Callable FHLB borrowings Advances from Federal Home Loan Banks Term borrowing with a bank Short-term Bank Loans and Notes Payable Trust Preferred Debentures Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Ownership [Axis] Ownership [Axis] Ownership [Domain] Ownership [Domain] Madison Statutory Trust I Madison Statutory Trust I [Member] Information pertaining to Madison Statutory Capital Trust I. Leesport Capital Trust II Leesport Capital Trust II [Member] Information pertaining to Leesport Capital Trust I. Sleepy Hollow Capital Trust I Sleepy Hollow Capital Trust I [Member] Information pertaining to Sleepy Hollow Capital Trust I. Subsidiary Name [Axis] Subsidiary Name [Axis] Subsidiary Name [Axis] Subsidiary Name [Domain] Subsidiary Name [Domain] [Domain] for Subsidiary Name [Axis] Tompkins Capital Trust I Tompkins Capital Trust I [Member] Information pertaining to Tompkins Capital Trust I. Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Unconsolidated subsidiary Variable Interest Entity, Not Primary Beneficiary [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Number of unconsolidated subsidiary trusts Nature Of Operations, Number Of Unconsolidated Subsidiary Trusts Nature of Operations, Number of Unconsolidated Subsidiary Trusts Ownership percentage by parent Noncontrolling Interest, Ownership Percentage by Parent Par Amount Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust Interest rate, basis spread Debt Instrument, Basis Spread on Variable Rate Common equity securities issued to the Company Common Equity Securities Issued To The Company The value of common equity securities issued to the Company from the trust. Proceeds of these offerings were used to acquire Subordinated Debentures currently held in trust. Other Borrowings Debt Disclosure [Text Block] 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] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balances at beginning Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Net income attributable to noncontrolling interests and Tompkins Financial Corporation Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax 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 Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Shares issued for dividend reinvestment plan Stock Issued During Period, Value, Dividend Reinvestment Plan Shares issued for employee stock ownership plan Stock Issued During Period, Value, Employee Stock Ownership Plan Directors deferred compensation plan Stock Granted, Value, Share-based Compensation, Net of Forfeitures Restricted stock activity Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Adoption of ASU Shares issued for purchase acquisition Stock Issued During Period, Value, Acquisitions Partial repurchase of noncontrolling interest Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Dividend to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Balances at ending Condensed Financial Information Disclosure [Abstract] Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Tompkins (the Parent Company) Parent Company [Member] Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net Income 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] Equity in undistributed earnings of subsidiaries Equity in undistributed earnings of subsidiaries Net income of the subsidiaries associated with a parent company. 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 [Abstract] Other, net Payments for (Proceeds from) Other Investing Activities Net Cash Provided by Investing Activities Net Cash Provided by (Used in) Investing Activities Financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Borrowings, net Proceeds from (Repayments of) Debt Cash dividends Payments of Ordinary Dividends, Common Stock Repurchase of common shares Payments for Repurchase of Common Stock Redemption of trust preferred debentures Payments for Repurchase of Trust Preferred Securities Shares issued for dividend reinvestment plans Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan Shares issued for employee stock ownership plan Proceeds from Stock Plans Proceeds from stock option exercises Proceeds from Stock Options Exercised Net Cash Used in Financing Activities Net Cash Provided by (Used in) Financing Activities Net (Decrease) Increase Cash and Cash Equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of year Cash and Cash Equivalents, at Carrying Value Total Cash & Cash Equivalents at End of Year Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Banking Banking [Member] 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. Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Balance at the beginning of the period Goodwill Goodwill related to sale of portion of business unit Goodwill, Written off Related to Sale of Business Unit Balance at the end of the period Reduction of goodwill Impairment of goodwill and intangible assets Goodwill and Intangible Asset Impairment Estimated amortization expense: Estimated amortization expense: For the year ended December 31, 2019 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months For the year ended December 31, 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Two For the year ended December 31, 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Three For the year ended December 31, 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Four For the year ended December 31, 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Five Amortization of mortgage servicing assets Amortization of Mortgage Servicing Rights (MSRs) Income Tax Disclosure [Abstract] Schedule of income tax (benefit) expense attributable to income from operations Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of effective income tax rate reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of deferred tax assets and liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Available-for-sale securities: Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] Plan actuarial loss Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] Net retirement plan prior service (cost) credit 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] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Before-Tax Amount Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax [Abstract] Change in net unrealized gains (losses) during the period Other Comprehensive Income (Loss), before Reclassifications, before Tax Reclassification adjustment for net realized loss on sale included in available-for-sale securities Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Other Comprehensive Income, Net unrealized losses Other Comprehensive Income (Loss), before Tax Tax (Expense) Benefit Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax [Abstract] Change in net unrealized loss during the period Other Comprehensive Income (Loss) before Reclassifications, Tax Reclassification adjustment for net realized loss on sale included in available-for-sale securities Reclassification from AOCI, Current Period, Tax Other Comprehensive Income, Net unrealized losses Other Comprehensive Income (Loss), Tax Net of Tax Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract] Change in net unrealized loss during the period Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Reclassification adjustment for net realized loss on sale included in available-for-sale securities Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Other comprehensive loss Stock Plans and Stock Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Statutory federal income tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State income taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Tax exempt income Effective Income Tax Rate Reconciliation, Tax Exempt Income, Percent Excess benefits from equity-based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent Bank-owned life insurance income Effective Income Tax Rate Reconciliation, Tax Exempt Life Insurance Income, Percent Effective Income Tax Rate Reconciliation, Tax Exempt Life Insurance Income, Percent Federal tax credit Effective Income Tax Rate Reconciliation, Tax Credit, Percent Enactment of Federal tax reform Effective Income Tax Rate Reconciliation, Tax Cuts And Jobs Act Of 2017, Percent Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act of 2017, Percent All other Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Total Effective Income Tax Rate Reconciliation, Percent Schedule of securities sold under agreements to repurchase Schedule of Repurchase Agreements [Table Text Block] Finance Leases 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 Loans and Leases Receivable, Allowance Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Loan to Value [Axis] Loan to Value [Axis] Loan to Value [Domain] Loan to Value [Domain] LTV 80 to 100 Percent LTV 80 to 100 Percent [Member] Tompkins, Cayuga, Cortland and Schuyler Counties, New York Wyoming, Livingston, Genessee, Orleans and Monroe, New York Putnam Country, Dutchess Country and Westchester, New York Berks, Montgomery, Philadelphia, Deleware and Schuylkill, Pennsylvania Business Acquisition [Line Items] Business Acquisition [Line Items] Loan to value - fixed rate loans (percent) Loan To Value - Fixed Rate Loans Loan-to-value (LTV) ratio for fixed rate loans. Loan to value - adjusted rate loans (percent) Loan To Value - Adjusted Rate Loans Loan-to-value (LTV) ratio for adjustable rate loans. Loan to value - private mortgage insurance (percent) Loan To Value - Private Mortgage Insurance Loan-to-value (LTV) ratio for loans requiring private mortgage insurance that reduced ltv exposure. Initial rate below the fully indexed rate, percent (less than) Mortgage Loans On Real Estate, Difference Between Initial Rate And Fully Indexed Rate, Percent Mortgage Loans On Real Estate, Initial Rate Below The Fully Indexed Rate, Percent Sale of residential mortgage loans Proceeds from Sale of Mortgage Loans Held-for-sale Net gains on sale of residential mortgage loans Gain (Loss) on Sale of Mortgage Loans Mortgage servicing assets added during the period Servicing Asset at Amortized Cost, Additions Residential mortgage loans serviced Residential mortgage loans serviced This is the average principal amount (during the year) of the securitized and unsecuritized financial assets. Mortgage servicing rights, amortized cost Servicing Asset at Amortized Cost Mortgage servicing rights (MSR) impairment Mortgage Servicing Rights (MSR) Impairment (Recovery) Loans held for sale Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Other Residential mortgage loans used to secure advances from FHLB Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged Loan to value - debt service coverage ratio Maximum Loan To Value Maximum Loan To Value Interest income on nonaccrual loans Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans Loans and leases receivable, impaired, commitments to lend to nonperforming loans Loans and Leases Receivable, Impaired, Commitments To Lend To Nonperforming Loans Loans and Leases Receivable, Impaired, Commitments To Lend To Nonperforming Loans Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Financing Receivable, Modifications [Line Items] Financing Receivable, Modifications [Line Items] Number of Loans Financing Receivable, Modifications, Number of Contracts Pre-Modification Outstanding Recorded Investment Financing Receivable, Modifications, Pre-Modification Recorded Investment Post- Modification Outstanding Recorded Investment Financing Receivable, Modifications, Post-Modification Recorded Investment Number of Loans TDRs Financing Receivable, Modifications, Subsequent Default, Number of Contracts Post- Modification Outstanding Recorded Investment TDRs Financing Receivable, Modifications, Subsequent Default, Recorded Investment Investments, Debt and Equity Securities [Abstract] 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] Equity securities Equity Securities [Member] Obligations of U.S. sponsored entities Obligations of U.S. Sponsored Entities [Member] Debentures, bonds and other debt securities issued by US government sponsored entities (GSEs), for example, but not limited to, Federal Home Loan Mortgage Corporation (FHLMC or Freddie Mac), Federal National Mortgage Association (FNMA or Fannie Mae), and the Federal Home Loan Bank (FHLB). Excludes debt issued by the Government National Mortgage Association (GNMA or Ginnie Mae). Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Available-for-Sale Securities Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Fair Value Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract] Less than 12 Months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months 12 Months or Longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Total Debt Securities, Available-for-sale, Unrealized Loss Position Less than 12 Months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value 12 Months or Longer Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Total Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Unrealized Losses Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract] Less than 12 Months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 12 Months or Longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Less than 12 Months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 12 Months or Longer Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Held-to-Maturity Securities Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position [Abstract] Fair Value Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract] Less than 12 Months Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value 12 Months or Longer Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value Total Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value Unrealized Losses Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss [Abstract] Less than 12 Months Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 12 Months or Longer Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Stock Options And Stock Appreciation Rights Stock Options And Stock Appreciation Rights [Member] Stock Options And Stock Appreciation Rights [Member]. Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of Shares/Rights Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding, beginning balance (in shares) Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding, ending balance (in shares) Exercisable, ending balance (in shares) Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding, beginning balance (in dollars per share) Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Outstanding, ending balance (in dollars per share) Exercisable, ending balance (in dollars per share) Weighted Average Remaining Contractual Term Weighted Average Remaining Contractual Term Outstanding (in years) Exercisable (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Aggregate Intrinsic Value Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Cash dividends (in dollars per share) Common Stock, Dividends, Per Share, Declared Net exercise of stock options and related tax benefit (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 dividend reinvestment plan (in shares) Stock Issued During Period, Shares, Dividend Reinvestment Plan Shares issued for employee stock ownership plan (in shares) Stock Issued During Period, Shares, Employee Stock Ownership Plan Directors deferred compensation plan (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Restricted stock activity (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Shares issued for purchase acquisition (in shares) Stock Issued During Period, Shares, Acquisitions Components of net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of prior service (credit) cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Recognized net actuarial loss Defined Benefit Plan, Amortization of Gain (Loss) Net periodic benefit (credit) cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss) Other changes in plan assets and benefit obligations recognized in other comprehensive income Net actuarial loss (gain) Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Recognized actuarial loss Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Prior service credit Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax Recognized prior service cost (credit) Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax Recognized in other comprehensive income (loss) Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Total recognized in net periodic benefit cost and other comprehensive income Defined Benefit Plan, Amount Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Income) Loss, before Tax Defined Contribution Plan [Table] Defined Contribution Plan [Table] Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation [Axis] Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation [Axis] Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation [Domain] Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation [Domain] Deferred Compensation Arrangement with Individual, by Type of Compensation, Pension and Other Postretirement Benefits Deferred Compensation Arrangement with Individual, by Type of Compensation, Pension and Other Postretirement Benefits [Member] DC Retirement Plan Defined Contribution Plan Disclosure [Line Items] Defined Contribution Plan Disclosure [Line Items] Number of non-contributory defined-contribution retirement plans Defined Contribution Plan, Number Of Non-Contributory Defined-Contribution Retirement Plans Defined Contribution Plan, Number Of Non-contributory Defined-contribution Retirement Plans Common Stock, issued (in shares) Common Stock, Shares, Issued Common stock, value Common Stock, Value, Issued Requisite service period Deferred Compensation Arrangement with Individual, Requisite Service Period To Participate In Pension Plan Deferred Compensation Arrangement with Individual, Requisite Service Period To Participate In Pension Plan Expenses related to defined-contribution plans Defined Contribution Plan, Cost Maximum annual contribution, percent of account balances, percent Defined Benefit Plan, Maximum Annual Contribution, Percent of Account Balances, Percent Defined Benefit Plan, Maximum Annual Contribution, Percent of Account Balances, Percent Accumulated benefit obligation Defined Benefit Plan, Accumulated Benefit Obligation Unfunded status recognized in other liabilities Rate of compensation increase (percent) Increase in service and interest costs Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components Increase in benefit obligation amount Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation Decrease in service and interest costs Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components Decrease in benefit obligation, amount Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation Expected long-term return on plan assets (percent) Employee stock ownership plan - expense recognized Employee Stock Ownership Plan (ESOP), Compensation Expense Incentive stock options (ISOPs), maximum contribution, percent Employee Stock Ownership Plan (ESOP), Incentive Stock Options (ISOPs), Maximum Employer Matching Contribution, Percent of Match Employee Stock Ownership Plan (ESOP), Incentive Stock Options (ISOPs), Maximum Employer Matching Contribution, Percent of Match Matching contributions to 401(k) plan cost Matching contributions to 401(k) plan cost The amount of matching contributions for the 401(k) plan the company has made during the period. Corporate owned life insurance Bank Owned Life Insurance Benefit liability Liability, Defined Benefit Pension Plan, Noncurrent Compensation expense Employee Benefits and Share-based Compensation Schedule of tax effect allocated to each component of other comprehensive income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Schedule of accumulated other comprehensive income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Segment and Related Information Segment Reporting Disclosure [Text Block] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Equity securities Defined Benefit Plan, Equity Securities [Member] Debt securities Defined Benefit Plan, Debt Security [Member] Other Other Investments [Member] Weighted-average asset allocations Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] ASSETS Assets [Abstract] Cash Cash Investment in subsidiaries, at equity Equity Method Investments Other Other Assets Total Assets Assets Liabilities and Shareholders’ Equity Liabilities and Equity [Abstract] Borrowings Debt and Capital Lease Obligations Trust preferred debentures issued to non-consolidated subsidiary Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount Other liabilities Other Liabilities Tompkins Financial Corporation Shareholders’ Equity Stockholders' Equity Attributable to Parent Total Liabilities and Equity Liabilities and Equity 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 for loan and lease losses Provision for Loan and Lease Losses Ending Balance Income Taxes Income Tax Disclosure [Text Block] Securities Sold Under Agreements to Repurchase and Federal Funds Purchased Repurchase Agreements, Resale Agreements, Securities Borrowed, and Securities Loaned Disclosure [Text Block] Net actuarial loss (gain) Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax Prior service cost (credit) Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax Total Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax Actuarial loss Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year Prior service cost Defined Benefit Plan, Expected Amortization of Prior Service Cost (Credit), Next Fiscal Year Total Defined Benefit Plan, Expected Amortization, Next Fiscal Year Revenue from Contract with Customer [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] 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 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 (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 Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-maturity [Table] 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 Debt Securities, Held-to-maturity, Fair Value Schedule of goodwill Schedule of Goodwill [Table Text Block] Schedule of amortizing intangible assets Schedule of Intangible Assets and Goodwill [Table Text Block] Schedule of estimated amortization expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] The Company (consolidated) Consolidated Entities [Member] Trust Company Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Castile Castile [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Mahopac Mahopac [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. VIST VIST [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Reclassification from accumulated other comprehensive income (loss) to retained earnings Tax Cuts And Jobs Act Of 2017, Reclassification From AOCI To Retained Earnings, Tax Effect Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings, Tax Effect Total Capital (to risk-weighted assets) Capital [Abstract] Total Capital (to risk-weighted assets), Actual Amount Capital Total Capital (to risk-weighted assets), Actual Ratio Capital to Risk Weighted Assets Total Capital (to risk-weighted assets), Required to be Adequately Capitalized, Amount Capital Required for Capital Adequacy Total Capital (to risk-weighted assets), Required to be Adequately Capitalized, Ratio Capital Required for Capital Adequacy to Risk Weighted Assets Total Capital (to risk-weighted assets), Required to be Well Capitalized, Amount Capital Required to be Well Capitalized Total Capital (to risk-weighted assets), Required to be Well Capitalized, Ratio Capital Required to be Well Capitalized to Risk Weighted Assets Common EquityTier 1 Capital (to risk-weighted assets) Common Equity Tier 1 Capital (To Risk-weighted Assets) Common Equity Tier 1 Capital (to risk-weighted assets), Actual Amount Common Equity Tier One Capital Common Equity Tier 1 Capital (to risk-weighted assets), Actual Ratio Common Equity Tier One Capital Ratio Common Equity Tier 1 Capital (to risk-weighted assets), Required to be Adequately Capitalized, Amount Minimum amount of Common Equity Tier 1 Capital for adequacy purposes The minimum amount of Common Equity Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action. Common Equity Tier 1 Capital (to risk-weighted assets), Required to be Adequately Capitalized, Ratio Minimum amount of Common Equity Tier 1 Capital for adequacy purposes, ratio The minimum Common Equity Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. Common Equity Tier 1 Capital (to risk-weighted assets), Required to be Well Capitalized, Amount Minimum Common Equity Tier 1 Capital required to be well-capitalized The Tier 1 capital amount (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. Common Equity Tier 1 Capital (to risk-weighted assets), Required to be Well Capitalized, Ratio Minimum Common Equity Tier 1 Capital required to be well-capitalized, ratio The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. Tier 1 Capital (to risk-weighted assets) Tier 1 Capital (To Risk-weighted Assets) Tier 1 Capital (to risk-weighted assets), Actual Amount Tier One Risk Based Capital Tier 1 Capital (to risk-weighted assets), Actual Ratio Tier One Risk Based Capital to Risk Weighted Assets Tier 1 Capital (to risk-weighted assets), Required to be Adequately Capitalized, Amount Tier One Risk Based Capital Required for Capital Adequacy Tier 1 Capital (to risk-weighted assets), Required to be Adequately Capitalized, Ratio Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Tier 1 Capital (to risk-weighted assets), Required to be Well Capitalized, Amount Tier One Risk Based Capital Required to be Well Capitalized Tier 1 Capital (to risk-weighted assets), Required to be Well Capitalized, Ratio Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 Capital (to average assets) Tier 1 Leverage Capital (To Average Assets) Tier 1 Capital (to average assets), Actual Amount Tier One Leverage Capital Tier 1 Capital (to average assets), Actual Ratio Tier One Leverage Capital to Average Assets Tier 1 Capital (to average assets), Required to be Adequately Capitalized, Amount Tier One Leverage Capital Required for Capital Adequacy Tier 1 Capital (to average assets), Required to be Adequately Capitalized, Ratio Tier One Leverage Capital Required for Capital Adequacy to Average Assets Tier 1 Capital (to average assets), Required to be Well Capitalized, Amount Tier One Leverage Capital Required to be Well Capitalized Tier 1 Capital (to average assets), Required to be Well Capitalized, Ratio Tier One Leverage Capital Required to be Well Capitalized to Average Assets 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 Due after ten years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Amortized Cost Total held-to-maturity debt securities Debt Securities, Held-to-maturity 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 Due after ten years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Total held-to-maturity debt securities Gross rental expense Operating Leases, Rent Expense, Net Renewal option (in years) Renewal option The number of years for lease renewal options. Schedule of other income and operating expense Schedule of Other Nonoperating Income (Expense) [Table Text Block] Debt securities Debt Securities [Member] Mortgage-backed securities Collateralized Mortgage Backed Securities [Member] Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost [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 Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value [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 available-for-sale debt securities Debt Securities, Available-for-sale Schedule of available for sale, debt securities Debt Securities, Available-for-sale [Table Text Block] Schedule of available for sale securities Available-for-sale Securities [Table Text Block] Schedule of held to maturity securities Debt Securities, Held-to-maturity [Table Text Block] Schedule of debt securities, available for sale with unrealized losses Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block] Schedule of available for sale securities with unrealized losses Available-for-sale Securities, Continuous 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] Schedule of Realized Gain (Loss) [Table Text Block] Schedule of Realized Gain (Loss) [Table Text Block] Statement of Financial Position [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 Available-for-sale securities, at fair value (amortized cost of $1,363,902 at December 31, 2018 and $1,408,996 at December 31, 2017) Held-to-maturity securities, at amortized cost (fair value of $139,377 at December 31, 2018 and $140,315 at December 31, 2017) Equity securities, at fair value (amortized cost $1,000 at December 31, 2018 and $1,000 at December 31, 2017) 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 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 Goodwill Other intangible assets, net Intangible Assets, Net (Excluding Goodwill) Accrued interest and other assets Interest Receivable and Other 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 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 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: 15,348,287 at December 31, 2018; and 15,301,524 at December 31, 2017 Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Treasury stock, at cost – 122,227 shares at December 31, 2018, and 120,805 shares at December 31, 2017 Treasury Stock, Value Total Tompkins Financial Corporation Shareholders’ Equity Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total Equity Disaggregation of Noninterest Income Disaggregation of Revenue [Table Text Block] Fair Value Disclosures [Abstract] Schedule of assets and liabilities measured at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of assets and liabilities measured at fair value on a non recurring basis Fair Value Measurements, Nonrecurring [Table Text Block] Schedule of carrying amount and fair value of financial instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Revenue, Initial Application Period Cumulative Effect Transition [Table] Revenue, Initial Application Period Cumulative Effect Transition [Table] Contingent Income [Member] Contingent Income [Member] Contingent Income [Member] 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, Net Contract with customer, liability Contract with Customer, Liability Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Weighted per share average fair value at grant date (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected dividend yield