PARENT COMPANY FINANCIAL INFORMATION - Schedule of STATEMENTS OF INCOME (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
STATEMENTS OF INCOME [Abstract]
Interest expense	$ 45,678	$ 53,505
Income before income tax expense	19,936	30,085
Income tax benefit	4,832	6,414
Net income	15,104	23,671
Parent Company
STATEMENTS OF INCOME [Abstract]
Dividends from subsidiary bank and non-bank	6,325	1,475
Interest and dividend income	8	35
Interest expense	2,003	0
Non-interest income	9	(24)
Non-interest expense	377	296
Income before impact of subsidiaries' undistributed earnings	3,962	1,190
Income before income tax expense	14,445	23,566
Income tax benefit	(659)	(105)
Net income	15,104	23,671
Parent Company | Chemung Canal Trust Company
STATEMENTS OF INCOME [Abstract]
Income (loss) from equity method investments	10,381	22,344
Parent Company | CFS Group Inc.
STATEMENTS OF INCOME [Abstract]
Income (loss) from equity method investments	$ 102	$ 32