| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| OPERATING ACTIVITIES | | | | | | | | |
| Net income attributable to Tompkins Financial Corporation | 8.5 | 19.4 | 19.5 | 21.3 | 20.9 | 23.3 | 19.5 | 21.3 |
| Depreciation and amortization of premises, equipment, and software | 2.7 | 2.7 | 2.7 | 2.7 | 2.6 | 2.7 | 2.6 | 2.6 |
| Amortization of intangible assets | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 | 0.2 | 0.3 | 0.3 |
| Earnings from corporate owned life insurance | -0.6 | -0.6 | -0.8 | 0.2 | -0.2 | -0.4 | -0.4 | -0.4 |
| Net amortization on securities | 0.9 | 1.0 | 1.1 | 1.2 | 1.5 | 1.8 | 2.4 | 2.5 |
| Amortization/accretion related to purchase accounting | -0.2 | -0.2 | -0.2 | -0.2 | -0.3 | -0.2 | -2.1 | 1.0 |
| Net loss on securities transactions | 7.1 | 0.0 | 0.5 | 0.1 | 0.0 | 0.0 | 0.0 | 0.1 |
| Net gain on sale of loans originated for sale | 0.0 | 0.0 | 0.0 | -0.1 | -0.1 | 0.0 | -0.1 | -0.3 |
| Proceeds from sale of loans originated for sale | 0.8 | 1.3 | 1.6 | 7.1 | 0.2 | 0.1 | 3.8 | 11.2 |
| Loans originated for sale | -1.0 | -1.5 | -1.5 | -6.0 | -0.4 | -0.7 | -4.0 | -8.1 |
| Net gain on sale of bank premises and equipment | 0.0 | 0.0 | 0.0 | -0.1 | 0.0 | 0.0 | 0.0 | |
| Net excess tax benefit from stock based compensation | 0.0 | 0.0 | 0.3 | 0.0 | 0.0 | 0.0 | 0.3 | 0.1 |
| Stock-based compensation expense | 1.1 | 1.0 | 1.3 | 1.1 | 1.0 | 0.9 | 1.3 | 1.4 |
| Decrease in accrued interest receivable | 0.6 | 0.2 | 0.0 | 0.3 | 0.3 | -0.1 | -9.5 | 4.2 |
| Increase (decrease) in accrued interest payable | -0.5 | 1.2 | -2.2 | 0.1 | -1.1 | 1.0 | 10.3 | -0.5 |
| Other, net | 0.3 | -1.0 | -3.6 | 1.6 | 2.2 | -4.3 | -2.1 | 3.7 |
| Net Cash Provided by Operating Activities | 22.0 | 22.8 | 21.0 | 30.8 | 27.6 | 23.9 | 29.8 | 40.9 |
| |
| INVESTING ACTIVITIES | | | | | | | | |
| Proceeds from maturities, calls and principal paydowns of available-for-sale debt securities | 43.4 | 35.6 | 29.4 | 44.7 | 54.9 | 79.8 | 76.1 | 119.8 |
| Proceeds from sales of available-for-sale debt securities | 73.8 | | 136.0 | 24.6 | | | | 103.8 |
| Purchases of available-for-sale debt securities | -17.8 | -0.3 | 0.0 | -5.7 | -24.5 | -124.7 | -69.8 | -289.3 |
| Purchases of held-to-maturity securities | | | | | -8.8 | -19.5 | -14.8 | -117.4 |
| Net increase in loans | -81.8 | -3.2 | -61.0 | -47.0 | -97.7 | 12.7 | 14.6 | 75.5 |
| Proceeds from sale/redemptions of Federal Home Loan Bank stock | 29.2 | 25.5 | 24.3 | 32.0 | 12.4 | 12.8 | | 5.6 |
| Purchases of Federal Home Loan Bank and other stock | -33.6 | -27.1 | -32.8 | -23.2 | -23.2 | -8.9 | -0.6 | |
| Proceeds from sale of bank premises and equipment | 0.0 | 0.1 | 0.0 | 0.1 | 0.1 | 0.0 | 0.0 | |
| Purchases of bank premises, equipment and software | -1.9 | -1.4 | -2.0 | -1.4 | -4.7 | 0.0 | -1.4 | -1.4 |
| Other, net | | -0.1 | -0.3 | | -0.1 | | -0.1 | |
| Net Cash Provided by (Used in) Investing Activities | 11.4 | 29.1 | 107.1 | 24.0 | -91.7 | -47.9 | 4.1 | -103.4 |
| |
| FINANCING ACTIVITIES | | | | | | | | |
| Net (decrease) increase in demand, money market, and savings deposits | -99.6 | -187.2 | -180.9 | | -226.1 | 249.0 | | |
| Net increase (decrease) in time deposits | 45.4 | 94.0 | | | -21.0 | -23.6 | | |
| Increase in other borrowings | 60.1 | 85.0 | 200.3 | | 235.6 | | | |
| Repayment of other borrowings | | -49.3 | -10.0 | -194.6 | | -64.0 | | -137.9 |
| Common stock issued | | | | | | | | |
| Repurchase of common stock | -6.4 | | | -1.3 | -3.8 | -10.4 | -2.6 | -13.2 |
| Shares issued for employee stock ownership plan | | | | | | 3.0 | | |
| Net shares issued related to restricted stock awards | -0.2 | 0.0 | -1.7 | -0.1 | 0.0 | 0.0 | -2.2 | -0.1 |
| Net proceeds from exercise of stock options | 0.0 | -0.1 | -0.5 | 0.0 | | 2.9 | -0.1 | -0.2 |
| Net Cash (Used in) Provided by Financing Activities | -22.4 | -59.1 | -153.9 | -31.6 | -30.6 | 135.9 | -304.3 | 105.0 |
| |
| Supplemental Information: | | | | | | | | |
| Cash paid during the year for - Interest | 19.6 | 14.9 | 9.8 | 5.6 | 2.8 | 2.8 | 1.0 | 5.6 |
| Cash paid during the year for - Taxes | 6.8 | 1.2 | 6.4 | 6.7 | 9.5 | 1.4 | 5.2 | 4.0 |
| Transfer of loans to other real estate owned | | | 0.0 | 0.2 | 0.0 | 0.0 | | 0.0 |
| Right-of-use assets obtained in exchange for new lease liabilities | 0.0 | 0.4 | 0.0 | 1.9 | 0.0 | 0.6 | 1.1 | 1.2 |