PARENT COMPANY FINANCIAL INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets:
Cash on deposit with subsidiary bank	$ 24,886	$ 28,130
Securities available for sale, at estimated fair value	344,820	280,507
Total assets	1,619,964	1,524,539	$ 1,476,143
Liabilities and shareholders' equity:
Dividends payable	1,214	1,204	1,195
Total liabilities	1,482,722	1,390,911
Shareholders' equity:
Total shareholders' equity	137,242	133,628	138,578	$ 131,115
Total liabilities and shareholders' equity	1,619,964	1,524,539
STATEMENTS OF INCOME [Abstract]
Income before income tax expense	14,091	11,866	12,553
Income tax benefit	4,658	3,709	3,822
Net income	9,433	8,157	8,731
Cash flows from operating activities:
Net income	9,433	8,157	8,731
Adjustments to reconcile net income to net cash provided by operating activities:
Change in other assets	4,931	(7,579)	(4,246)
Change in other liabilities	(9,421)	15,086	9,403
Net cash provided by operating activities	14,123	18,443	22,972
Cash flow from financing activities:
Purchase of treasury stock	0	0	(93)
Sale of treasury stock	438	0	71
Net cash provided by financing activities	97,547	30,249	34,883
Increase (decrease) in cash and cash equivalents	(2,978)	(22,446)	11,368
Cash and cash equivalents, beginning of period	29,163	51,609	40,241
Cash and cash equivalents, end of period	26,185	29,163	51,609
Parent Company
Assets:
Cash on deposit with subsidiary bank	1,795	3,200
Dividends receivable from subsidiary bank	1,214	1,204
Securities available for sale, at estimated fair value	337	346
Other assets	907	1,129
Total assets	138,510	134,868
Liabilities and shareholders' equity:
Dividends payable	1,214	1,204
Other liabilities	54	36
Total liabilities	1,268	1,240
Shareholders' equity:
Total shareholders' equity	137,242	133,628
Total liabilities and shareholders' equity	138,510	134,868
STATEMENTS OF INCOME [Abstract]
Dividends from subsidiary bank	2,424	4,805	4,778
Interest and dividend income	9	10	9
Other income	0	0	132
Operating expenses	270	261	324
Income before income tax expense	2,163	4,554	4,595
Income before income tax	9,264	7,990	8,607
Income tax benefit	(169)	(167)	(124)
Net income	9,433	8,157	8,731
Cash flows from operating activities:
Net income	9,433	8,157	8,731
Adjustments to reconcile net income to net cash provided by operating activities:
Change in dividend receivable	(10)	(9)	(1,195)
Change in other assets	222	126	558
Change in other liabilities	(23)	110	79
Expense related to employee stock compensation	93	117	112
Expense related to restricted stock units for directors' deferred compensation plan	95	94	99
Expense to employee restricted stock awards	314	151	131
Net cash provided by operating activities	3,023	5,310	4,503
Cash flow from financing activities:
Cash dividends paid	(4,833)	(4,796)	(3,583)
Purchase of treasury stock	(33)	0	(93)
Sale of treasury stock	438	0	71
Net cash provided by financing activities	(4,428)	(4,796)	(3,605)
Increase (decrease) in cash and cash equivalents	(1,405)	514	898
Cash and cash equivalents, beginning of period	3,200	2,686	1,788
Cash and cash equivalents, end of period	1,795	3,200	2,686
Parent Company | Chemung Canal Trust Company
Assets:
Investment in subsidiary	133,263	128,081
STATEMENTS OF INCOME [Abstract]
Equity in undistributed earnings	7,015	3,307	3,873
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings	(7,015)	(3,307)	(3,873)
Parent Company | CFS Group Inc.
Assets:
Investment in subsidiary	994	908
STATEMENTS OF INCOME [Abstract]
Equity in undistributed earnings	86	129	139
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings	$ (86)	$ (129)	$ (139)