Segment and Related Information - Schedule of Segment and Related Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Interest income	$ 60,953	$ 59,835	$ 120,129	$ 119,590
Interest expense	2,691	4,989	5,253	9,707
Net Interest Income	58,262	54,846	114,876	109,883
Provision for credit loss expense	856	(3,071)	336	(4,901)
Noninterest income	18,944	18,858	38,929	38,841
Noninterest expense	49,120	47,442	95,959	91,953
Income Before Income Tax Expense	27,230	29,333	57,510	61,672
Income tax expense	6,329	6,471	13,305	13,151
Net Income Attributable to Noncontrolling Interests and Tompkins Financial Corporation	20,901	22,862	44,205	48,521
Less: Net income attributable to noncontrolling interests	32	31	63	64
Net Income Attributable to Tompkins Financial Corporation	20,869	22,831	44,142	48,457
Depreciation and amortization	2,595	2,596	5,245	5,102
Assets	7,842,461	7,988,208	7,842,461	7,988,208		$ 7,819,982
Goodwill	92,447	92,447	92,447	92,447		92,447
Other intangibles, net	3,124	4,274	3,124	4,274		3,643
Net Loans and Leases	5,118,710	5,127,624	5,118,710	5,127,624
Deposits	6,769,521	6,837,000	6,769,521	6,837,000		6,791,435
Total Equity	624,318	728,253	624,318	728,253	$ 657,492	$ 728,941	$ 709,936	$ 717,689
Operating Segments | Banking
Segment Reporting Information [Line Items]
Interest income	60,953	59,843	120,129	119,597
Interest expense	2,692	4,997	5,255	9,716
Net Interest Income	58,261	54,846	114,874	109,881
Provision for credit loss expense	856	(3,071)	336	(4,901)
Noninterest income	6,329	6,447	12,522	12,759
Noninterest expense	39,395	37,879	76,584	73,206
Income Before Income Tax Expense	24,339	26,485	50,476	54,335
Income tax expense	5,465	5,729	11,630	11,243
Net Income Attributable to Noncontrolling Interests and Tompkins Financial Corporation	18,874	20,756	38,846	43,092
Less: Net income attributable to noncontrolling interests	32	31	63	64
Net Income Attributable to Tompkins Financial Corporation	18,842	20,725	38,783	43,028
Depreciation and amortization	2,515	2,527	5,093	4,965
Assets	7,786,614	7,987,751	7,786,614	7,987,751
Goodwill	64,500	64,370	64,500	64,370
Other intangibles, net	1,236	1,994	1,236	1,994
Net Loans and Leases	5,118,710	5,127,624	5,118,710	5,127,624
Deposits	6,786,754	6,851,924	6,786,754	6,851,924
Total Equity	563,994	667,007	563,994	667,007
Operating Segments | Insurance
Segment Reporting Information [Line Items]
Interest income	1	0	2	2
Interest expense	0	0	0	0
Net Interest Income	1	0	2	2
Provision for credit loss expense	0	0	0	0
Noninterest income	8,573	8,163	18,007	17,581
Noninterest expense	6,812	6,760	13,314	13,197
Income Before Income Tax Expense	1,762	1,403	4,695	4,386
Income tax expense	494	401	1,310	1,203
Net Income Attributable to Noncontrolling Interests and Tompkins Financial Corporation	1,268	1,002	3,385	3,183
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net Income Attributable to Tompkins Financial Corporation	1,268	1,002	3,385	3,183
Depreciation and amortization	44	55	88	110
Assets	47,222	46,590	47,222	46,590
Goodwill	19,866	19,866	19,866	19,866
Other intangibles, net	1,830	2,201	1,830	2,201
Net Loans and Leases	0	0	0	0
Deposits	0	0	0	0
Total Equity	34,860	33,101	34,860	33,101
Operating Segments | Wealth Management
Segment Reporting Information [Line Items]
Interest income	0	0	0	0
Interest expense	0	0	0	0
Net Interest Income	0	0	0	0
Provision for credit loss expense	0	0	0	0
Noninterest income	4,598	4,808	9,532	9,591
Noninterest expense	3,469	3,363	7,193	6,640
Income Before Income Tax Expense	1,129	1,445	2,339	2,951
Income tax expense	370	341	365	705
Net Income Attributable to Noncontrolling Interests and Tompkins Financial Corporation	759	1,104	1,974	2,246
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net Income Attributable to Tompkins Financial Corporation	759	1,104	1,974	2,246
Depreciation and amortization	36	14	64	27
Assets	26,915	30,435	26,915	30,435
Goodwill	8,081	8,211	8,081	8,211
Other intangibles, net	58	79	58	79
Net Loans and Leases	0	0	0	0
Deposits	(847)	0	(847)	0
Total Equity	25,464	28,145	25,464	28,145
Intercompany
Segment Reporting Information [Line Items]
Interest income	(1)	(8)	(2)	(9)
Interest expense	(1)	(8)	(2)	(9)
Net Interest Income	0	0	0	0
Provision for credit loss expense	0	0	0	0
Noninterest income	(556)	(560)	(1,132)	(1,090)
Noninterest expense	(556)	(560)	(1,132)	(1,090)
Income Before Income Tax Expense	0	0	0	0
Income tax expense	0	0	0	0
Net Income Attributable to Noncontrolling Interests and Tompkins Financial Corporation	0	0	0	0
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net Income Attributable to Tompkins Financial Corporation	0	0	0	0
Depreciation and amortization	0	0	0	0
Assets	(18,290)	(76,568)	(18,290)	(76,568)
Goodwill	0	0	0	0
Other intangibles, net	0	0	0	0
Net Loans and Leases	0	0	0	0
Deposits	(16,386)	(14,924)	(16,386)	(14,924)
Total Equity	$ 0	$ 0	$ 0	$ 0