Condensed Parent Company Only Financial Statements - Condensed Statement of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Income Statements, Captions [Line Items]
Interest expense	$ 28,991	$ 50,750	$ 39,792
Income tax benefit	(19,924)	(21,016)	(21,805)
Net Income Attributable to Tompkins Financial Corporation	77,588	81,718	82,308
Tompkins (the Parent Company)
Condensed Income Statements, Captions [Line Items]
Dividends received from subsidiaries	60,818	72,827	44,518
Other income	52	240	332
Total Operating Income	60,870	73,067	44,850
Interest expense	1,241	1,450	1,468
Other expenses	9,184	8,409	7,222
Total Operating Expenses	10,425	9,859	8,690
Earnings of Subsidiaries	50,445	63,208	36,160
Income tax benefit	2,160	2,085	1,687
Equity in undistributed earnings of subsidiaries	24,983	16,425	44,461
Net Income Attributable to Tompkins Financial Corporation	$ 77,588	$ 81,718	$ 82,308