CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive (Loss) Income	Treasury Stock	Non- controlling Interests
Beginning balances at Dec. 31, 2019	$ 663,054	$ 1,707	$ 1,501	$ 338,507	$ 370,477	$ 1,707	$ (43,564)	$ (5,279)	$ 1,412
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to noncontrolling interests and Tompkins Financial Corporation	53,711				53,610				101
Other comprehensive income (loss)	19,700						19,700
Subtotal comprehensive income attributable to noncontrolling interests and Tompkins Financial Corporation	73,411
Cash dividends	(23,296)				(23,296)
Net exercise of stock options	(248)			(248)
Common stock repurchased and returned to unissued status	(5,620)		(7)	(5,613)
Shares issued for dividend reinvestment plan	1,529		2	1,527
Stock-based compensation expense	3,372			3,372
Directors deferred compensation plan	0			76				(76)
Restricted stock activity	(292)			(292)
Partial repurchase of noncontrolling interest	(6)								(6)
Ending balances at Sep. 30, 2020	713,611		1,496	337,329	402,498		(23,864)	(5,355)	1,507
Beginning balances at Jun. 30, 2020	698,029		1,495	335,268	386,025		(21,048)	(5,187)	1,476
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to noncontrolling interests and Tompkins Financial Corporation	24,262				24,230				32
Other comprehensive income (loss)	(2,816)						(2,816)
Subtotal comprehensive income attributable to noncontrolling interests and Tompkins Financial Corporation	21,446
Cash dividends	(7,757)				(7,757)
Net exercise of stock options	(32)		0	(32)
Shares issued for dividend reinvestment plan	848		1	847
Stock-based compensation expense	1,078			1,078
Directors deferred compensation plan	0			168				(168)
Restricted stock activity	0			0
Partial repurchase of noncontrolling interest	(1)								(1)
Ending balances at Sep. 30, 2020	713,611		1,496	337,329	402,498		(23,864)	(5,355)	1,507
Beginning balances at Dec. 31, 2020	717,689		1,496	333,976	418,413		(32,074)	(5,534)	1,412
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to noncontrolling interests and Tompkins Financial Corporation	69,895				69,799				96
Other comprehensive income (loss)	(23,020)						(23,020)
Subtotal comprehensive income attributable to noncontrolling interests and Tompkins Financial Corporation	46,875
Cash dividends	(24,060)				(24,060)
Net exercise of stock options	(693)		1	(694)
Common stock repurchased and returned to unissued status	(21,177)		(27)	(21,150)
Shares issued for dividend reinvestment plan	2		0	2
Stock-based compensation expense	3,845			3,845
Directors deferred compensation plan	0			100				(100)
Restricted stock activity	(122)			(122)
Partial repurchase of noncontrolling interest	(2)								(2)
Ending balances at Sep. 30, 2021	722,357		1,470	315,957	464,152		(55,094)	(5,634)	1,506
Beginning balances at Jun. 30, 2021	728,253		1,487	327,881	450,773		(47,882)	(5,480)	1,474
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to noncontrolling interests and Tompkins Financial Corporation	21,374				21,342				32
Other comprehensive income (loss)	(7,212)						(7,212)
Subtotal comprehensive income attributable to noncontrolling interests and Tompkins Financial Corporation	14,162
Cash dividends	(7,963)				(7,963)
Net exercise of stock options	(190)			(190)
Common stock repurchased and returned to unissued status	(13,194)		(17)	(13,177)
Stock-based compensation expense	1,411			1,411
Directors deferred compensation plan	0			154				(154)
Restricted stock activity	(122)			(122)
Ending balances at Sep. 30, 2021	$ 722,357		$ 1,470	$ 315,957	$ 464,152		$ (55,094)	$ (5,634)	$ 1,506