Segment and Related Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Dec. 31, 2014
Interest income $ 51,077 $ 47,530 $ 150,803 $ 140,181    
Interest expense 5,760 5,144 16,541 15,237    
Net interest income 45,317 42,386 134,262 124,944    
Provision for loan and lease losses 782 281 2,615 1,412    
Noninterest income 17,905 17,422 52,492 54,030    
Noninterest expense 40,324 37,882 119,218 110,492    
Income before income tax expense 22,116 21,645 64,921 67,070    
Income tax expense 7,219 7,115 21,208 22,405    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 14,897 14,530 43,713 44,665    
Less: Net income attributable to noncontrolling interests 33 33 98 98    
Net income attributable to Tompkins Financial Corporation 14,864 14,497 43,615 44,567    
Depreciation and amortization 1,693 1,626 5,049 4,834    
Assets 6,102,215 5,594,718 6,102,215 5,594,718 $ 5,689,995  
Goodwill 92,623 92,243 92,623 92,243 91,792  
Other intangibles, net 11,902 13,028 11,902 13,028 12,448  
Net loans and leases 4,055,435 3,603,348 4,055,435 3,603,348 3,740,038  
Deposits 4,690,300 4,437,073 4,690,300 4,437,073 4,395,306  
Total Equity 561,190 517,959 561,190 517,959 $ 516,466 $ 489,583
Banking [Member]            
Interest income 51,077 47,490 150,803 140,066    
Interest expense 5,760 5,144 16,541 15,238    
Net interest income 45,317 42,346 134,262 124,828    
Provision for loan and lease losses 782 281 2,615 1,412    
Noninterest income 6,335 6,293 18,468 20,346    
Noninterest expense 31,337 29,247 92,357 85,092    
Income before income tax expense 19,533 19,111 57,758 58,670    
Income tax expense 6,238 6,156 18,513 19,260    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 13,295 12,955 39,245 39,410    
Less: Net income attributable to noncontrolling interests 33 33 98 98    
Net income attributable to Tompkins Financial Corporation 13,262 12,922 39,147 39,312    
Depreciation and amortization 1,587 1,503 4,724 4,465    
Assets 6,056,855 5,551,880 6,056,855 5,551,880    
Goodwill 64,370 64,500 64,370 64,500    
Other intangibles, net 6,778 8,173 6,778 8,173    
Net loans and leases 4,055,435 3,603,348 4,055,435 3,603,348    
Deposits 4,698,847 4,444,332 4,698,847 4,444,332    
Total Equity 518,707 478,567 518,707 478,567    
Insurance [Member]            
Interest income 0 0 1 2    
Interest expense 0 0 1 0    
Net interest income 0 0 0 2    
Provision for loan and lease losses 0 0 0 0    
Noninterest income 7,862 7,621 23,017 22,508    
Noninterest expense 6,281 6,069 18,780 17,653    
Income before income tax expense 1,581 1,552 4,237 4,857    
Income tax expense 642 634 1,719 1,951    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 939 918 2,518 2,906    
Less: Net income attributable to noncontrolling interests 0 0 0 0    
Net income attributable to Tompkins Financial Corporation 939 918 2,518 2,906    
Depreciation and amortization 87 93 269 276    
Assets 39,618 36,825 39,618 36,825    
Goodwill 20,042 19,662 20,042 19,662    
Other intangibles, net 4,748 4,388 4,748 4,388    
Net loans and leases 0 0 0 0    
Deposits 0 0 0 0    
Total Equity 30,780 27,776 30,780 27,776    
Wealth Management [Member]            
Interest income 0 40 0 114    
Interest expense 0 0 0 0    
Net interest income 0 40 0 114    
Provision for loan and lease losses 0 0 0 0    
Noninterest income 4,004 3,788 11,870 11,919    
Noninterest expense 3,002 2,846 8,944 8,490    
Income before income tax expense 1,002 982 2,926 3,543    
Income tax expense 339 325 976 1,194    
Net Income attributable to noncontrolling interests and Tompkins Financial Corporation 663 657 1,950 2,349    
Less: Net income attributable to noncontrolling interests 0 0 0 0    
Net income attributable to Tompkins Financial Corporation 663 657 1,950 2,349    
Depreciation and amortization 19 30 56 93    
Assets 14,366 13,782 14,366 13,782    
Goodwill 8,211 8,081 8,211 8,081    
Other intangibles, net 376 467 376 467    
Net loans and leases 0 0 0 0    
Deposits 0 0 0 0    
Total Equity 11,703 11,616 11,703 11,616    
Intercompany [Member]            
Interest income 0 0 (1) (1)    
Interest expense 0 0 (1) (1)    
Net interest income 0 0 0 0    
Provision for loan and lease losses 0 0 0 0    
Noninterest income (296) (280) (863) (743)    
Noninterest expense (296) (280) (863) (743)    
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 (8,624) (7,769) (8,624) (7,769)    
Goodwill 0 0 0 0    
Other intangibles, net 0 0 0 0    
Net loans and leases 0 0 0 0    
Deposits (8,547) (7,259) (8,547) (7,259)    
Total Equity $ 0 $ 0 $ 0 $ 0