PARENT COMPANY FINANCIAL INFORMATION - STATEMENTS OF INCOME (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
STATEMENTS OF INCOME [Abstract]
Income before income tax expense	$ 36,889	$ 33,760
Income tax benefit	8,106	7,335
Net income	28,783	26,425
Parent Company
STATEMENTS OF INCOME [Abstract]
Dividends from subsidiary bank and non-bank	7,051	6,854
Interest and dividend income	7	4
Non-interest income	10	85
Non-interest expenses	586	432
Income before impact of subsidiaries' undistributed earnings	6,482	6,511
Income before income tax expense	28,590	26,299
Income tax benefit	(193)	(126)
Net income	28,783	26,425
Parent Company | Chemung Canal Trust Company
STATEMENTS OF INCOME [Abstract]
Income (loss) from equity method investments	21,638	19,492
Parent Company | CFS Group Inc.
STATEMENTS OF INCOME [Abstract]
Income (loss) from equity method investments	220	198
Parent Company | Chemung Risk Management
STATEMENTS OF INCOME [Abstract]
Income (loss) from equity method investments	$ 250	$ 98