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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Loans, Premises and Equipment and Wealth Management and Group Fee Income (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022
Property, Plant and Equipment [Line Items] |  |
Period of delinquency after which a loan is placed on non-accrual status (days) | 90 days |
Assets under management | $ 2,242.0 | $ 2,053.0
Chemung Financial Corporation |  |
Property, Plant and Equipment [Line Items] |  |
Assets under management | $ 381.3 | $ 346.5
Buildings | Minimum |  |
Property, Plant and Equipment [Line Items] |  |
Estimated useful lives (years) | 15 years |
Buildings | Maximum |  |
Property, Plant and Equipment [Line Items] |  |
Estimated useful lives (years) | 50 years |
Equipment and Furniture | Minimum |  |
Property, Plant and Equipment [Line Items] |  |
Estimated useful lives (years) | 3 years |
Equipment and Furniture | Maximum |  |
Property, Plant and Equipment [Line Items] |  |
Estimated useful lives (years) | 10 years |

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- Definition Refers to the period of delinquency after which a loan is placed on non-accrual status. + References No definition available. + Details
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- Definition The carrying amount of assets an investment adviser manages on behalf of investors. + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
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