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LEASES - Narrative (Details) - USD ($) | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Jan. 28, 2021 | Nov. 30, 2020
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease, weighted average remaining lease term (years) | 10 years 3 months 18 days |  |  |  |
Operating lease, weighted average discount rate | 3.39% |  |  |  |
Rent expense | $ 1,000,000.0 | $ 1,000,000.0 |  |  |
Rent expense |  |  | $ 1,100,000 |  |
Operating lease, liability, termination |  |  |  |  | $ 200,000
Operating lease not yet commenced | 0 |  |  |  |
Operating lease right-of-use assets | 7,145,000 | 8,001,000 |  |  |
Operating lease liabilities | $ 7,264,000 | $ 8,084,000 |  |  |
Finance lease, weighted average remaining lease term (years) | 12 years 1 month 6 days |  |  |  |
Finance lease, weighted average discount rate | 3.36% |  |  |  |
Finance lease not yet commenced | $ 0 |  |  |  |
Branch Location, Western New York Location | Subsequent Event |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease, term (in years) |  |  |  | 3 years |
Operating lease right-of-use assets |  |  |  | $ 100,000 |
Operating lease liabilities |  |  |  | $ 100,000 |

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- Definition Weighted average discount rate for finance lease calculated at point in time. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (g)(4) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 55 -Paragraph 53 -URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971 + Details
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- Definition Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (g)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 55 -Paragraph 53 -URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971 + Details
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- Definition Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line. + 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 Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
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- Definition Amount of operating lease expense. Excludes sublease income. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918638-209977 + Details
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