Segment and Related Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Dec. 31, 2015
Segment Reporting Information [Line Items]            
Interest income $ 56,342 $ 50,417 $ 109,963 $ 99,726    
Interest expense 6,041 5,510 11,628 10,781    
Net Interest Income 50,301 44,907 98,335 88,945    
Provision for loan and lease losses 976 978 1,745 1,833    
Noninterest income 17,450 17,084 34,690 34,587    
Noninterest expense 41,568 39,388 82,936 78,894    
Income Before Income Tax Expense 25,207 21,625 48,344 42,805    
Income tax expense 8,248 6,760 15,637 13,656    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 16,959 14,865 32,707 29,149    
Less: Net income attributable to noncontrolling interests 33 32 65 65    
Net Income Attributable to Tompkins Financial Corporation 16,926 14,833 32,642 29,084    
Depreciation and amortization 1,854 1,671 3,641 3,356    
Assets 6,415,012 5,924,906 6,415,012 5,924,906 $ 6,236,756  
Goodwill 92,291 92,942 92,291 92,942 92,623  
Other intangibles, net 10,251 12,532 10,251 12,532 11,349  
Net loans and leases 4,381,439 3,944,988 4,381,439 3,944,988 4,222,278  
Deposits 4,750,722 4,469,721 4,750,722 4,469,721 4,625,139  
Total Equity 576,915 554,435 576,915 554,435 $ 549,405 $ 516,466
Operating Segments | Banking            
Segment Reporting Information [Line Items]            
Interest income 56,342 50,417 109,963 99,726    
Interest expense 6,041 5,510 11,628 10,781    
Net Interest Income 50,301 44,907 98,335 88,945    
Provision for loan and lease losses 976 978 1,745 1,833    
Noninterest income 6,720 5,861 13,123 12,132    
Noninterest expense 32,819 30,645 65,306 61,018    
Income Before Income Tax Expense 23,226 19,145 44,407 38,226    
Income tax expense 7,510 5,818 14,182 11,943    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 15,716 13,327 30,225 26,283    
Less: Net income attributable to noncontrolling interests 33 32 65 65    
Net Income Attributable to Tompkins Financial Corporation 15,683 13,295 30,160 26,218    
Depreciation and amortization 1,766 1,561 3,456 3,136    
Assets 6,368,374 5,877,758 6,368,374 5,877,758    
Goodwill 64,370 64,370 64,370 64,370    
Other intangibles, net 5,783 7,133 5,783 7,133    
Net loans and leases 4,381,439 3,944,988 4,381,439 3,944,988    
Deposits 4,761,017 4,477,266 4,761,017 4,477,266    
Total Equity 532,291 512,711 532,291 512,711    
Operating Segments | Insurance            
Segment Reporting Information [Line Items]            
Interest income 0 0 1 1    
Interest expense 0 0 0 1    
Net Interest Income 0 0 1 0    
Provision for loan and lease losses 0 0 0 0    
Noninterest income 7,132 7,556 14,448 15,155    
Noninterest expense 6,059 6,160 12,139 12,500    
Income Before Income Tax Expense 1,073 1,396 2,310 2,655    
Income tax expense 428 575 903 1,076    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 645 821 1,407 1,579    
Less: Net income attributable to noncontrolling interests 0 0 0 0    
Net Income Attributable to Tompkins Financial Corporation 645 821 1,407 1,579    
Depreciation and amortization 74 91 156 182    
Assets 41,438 41,272 41,438 41,272    
Goodwill 19,710 20,361 19,710 20,361    
Other intangibles, net 4,151 5,003 4,151 5,003    
Net loans and leases 0 0 0 0    
Deposits 0 0 0 0    
Total Equity 31,379 30,684 31,379 30,684    
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 loan and lease losses 0 0 0 0    
Noninterest income 4,015 3,956 7,925 7,866    
Noninterest expense 3,107 2,872 6,297 5,942    
Income Before Income Tax Expense 908 1,084 1,628 1,924    
Income tax expense 310 367 552 637    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 598 717 1,076 1,287    
Less: Net income attributable to noncontrolling interests 0 0 0 0    
Net Income Attributable to Tompkins Financial Corporation 598 717 1,076 1,287    
Depreciation and amortization 14 19 29 38    
Assets 15,692 13,701 15,692 13,701    
Goodwill 8,211 8,211 8,211 8,211    
Other intangibles, net 317 396 317 396    
Net loans and leases 0 0 0 0    
Deposits 0 0 0 0    
Total Equity 13,245 11,040 13,245 11,040    
Intercompany            
Segment Reporting Information [Line Items]            
Interest income 0 0 (1) (1)    
Interest expense 0 0 0 (1)    
Net Interest Income 0 0 (1) 0    
Provision for loan and lease losses 0 0 0 0    
Noninterest income (417) (289) (806) (566)    
Noninterest expense (417) (289) (806) (566)    
Income Before Income Tax Expense 0 0 (1) 0    
Income tax expense 0 0 0 0    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 0 0 (1) 0    
Less: Net income attributable to noncontrolling interests 0 0 0 0    
Net Income Attributable to Tompkins Financial Corporation 0 0 (1) 0    
Depreciation and amortization 0 0 0 0    
Assets (10,492) (7,825) (10,492) (7,825)    
Goodwill 0 0 0 0    
Other intangibles, net 0 0 0 0    
Net loans and leases 0 0 0 0    
Deposits (10,295) (7,545) (10,295) (7,545)    
Total Equity $ 0 $ 0 $ 0 $ 0