PARENT COMPANY FINANCIAL INFORMATION - Schedule of BALANCE SHEETS (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Assets:
Cash and cash equivalents	$ 22,772	$ 26,224
Total assets	2,710,235	2,776,147
Liabilities and shareholders' equity:
Subordinated debt, net	44,028	0
Total liabilities	2,455,526	2,560,838
Shareholders' equity:
Total shareholders' equity	254,709	215,309	$ 195,241
Total liabilities and shareholders' equity	2,710,235	2,776,147
Parent Company
Assets:
Cash and cash equivalents	6,826	2,252
Equity investments, at fair value	189	180
Other assets	2,793	1,977
Total assets	298,931	215,568
Liabilities and shareholders' equity:
Other liabilities	194	259
Total liabilities	44,222	259
Shareholders' equity:
Total shareholders' equity	254,709	215,309
Total liabilities and shareholders' equity	298,931	215,568
Parent Company | Chemung Canal Trust Company
Assets:
Investment in subsidiary	287,571	209,709
Parent Company | CFS Group Inc.
Assets:
Investment in subsidiary	$ 1,552	$ 1,450