SECURITIES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Realized loss	$ 0	$ 39
Tax benefit on realized loss		4
Proceeds from the sale of held to maturity securities	0	1,000
Loss on sale of held-to-maturity securities		25
Chemung Risk Management
Debt Securities, Available-for-sale [Line Items]
Proceeds from the sale of available for sale securities	0	1,200
Realized loss		14
Deferred Compensation Plan
Debt Securities, Available-for-sale [Line Items]
Investments, fair value	2,600	2,400
Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Investments, fair value	$ 600	$ 600

Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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Amount of realized gain (loss) from sale of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Amount of tax expense (benefit) from realized gain (loss) on investment and derivative, classified as operating. Investment includes, but is not limited to, debt and equity securities, security sold short, real estate, and commodity.

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