CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income attributable to noncontrolling interests and Tompkins Financial Corporation	$ 77,742	$ 81,845	$ 82,435
Available-for-sale securities:
Change in net unrealized gain (loss) during the period	16,894	25,241	(10,981)
Unrealized gains on HTM securities transferred to AFS securities	0	2,852	0
Reclassification adjustment for net realized (gain) loss on sale included in available-for-sale securities	(324)	(465)	332
Employee benefit plans:
Net retirement plan loss	(7,028)	(7,642)	(2,594)
Net actuarial gain due to curtailment	0	(302)	0
Net retirement plan prior service (credit) cost	0	(1,373)	0
Amortization of net retirement plan actuarial gain	1,786	1,266	1,298
Amortization of net retirement plan prior service cost	162	24	11
Other comprehensive income (loss)	11,490	19,601	(11,934)
Subtotal comprehensive income attributable to noncontrolling interests and Tompkins Financial Corporation	89,232	101,446	70,501
Less: Total comprehensive income attributable to noncontrolling interests	(154)	(127)	(127)
Total comprehensive income attributable to Tompkins Financial Corporation	$ 89,078	$ 101,319	$ 70,374