XML 93 R76.htm IDEA: XBRL DOCUMENT
v3.22.4

Loans (Retail Loan Portfolio Categorized by Performance Status) (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Residential Real Estate Loans [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | $ 79,882 | $ 92,699
Prior Fiscal Year 1 | 86,126 | 129,295
Prior Fiscal Year 2 | 119,329 | 86,101
Prior Fiscal Year 3 | 77,232 | 66,423
Prior Fiscal Year 4 | 56,197 | 51,831
Prior | 171,194 | 150,950
Revolving Loans Amortized Cost Basis | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 589,960 | 577,299
Residential Real Estate Loans [Member] | Performing [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 79,882 | 92,620
Prior Fiscal Year 1 | 85,821 | 129,240
Prior Fiscal Year 2 | 118,819 | 85,876
Prior Fiscal Year 3 | 76,437 | 65,866
Prior Fiscal Year 4 | 55,520 | 50,932
Prior | 169,410 | 150,392
Revolving Loans Amortized Cost Basis | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 585,889 | 574,926
Residential Real Estate Loans [Member] | Non-Performing [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 0 | 79
Prior Fiscal Year 1 | 305 | 55
Prior Fiscal Year 2 | 510 | 225
Prior Fiscal Year 3 | 795 | 557
Prior Fiscal Year 4 | 677 | 899
Prior | 1,784 | 558
Revolving Loans Amortized Cost Basis | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 4,071 | 2,373
Residential Real Estate Lines [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 0 | 0
Prior Fiscal Year 1 | 0 | 0
Prior Fiscal Year 2 | 0 | 0
Prior Fiscal Year 3 | 0 | 0
Prior Fiscal Year 4 | 0 | 0
Prior | 0 | 0
Revolving Loans Amortized Cost Basis | 70,976 | 70,560
Revolving Loans Converted to Term | 6,694 | 7,971
Total | 77,670 | 78,531
Residential Real Estate Lines [Member] | Performing [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 0 | 0
Prior Fiscal Year 1 | 0 | 0
Prior Fiscal Year 2 | 0 | 0
Prior Fiscal Year 3 | 0 | 0
Prior Fiscal Year 4 | 0 | 0
Prior | 0 | 0
Revolving Loans Amortized Cost Basis | 70,942 | 70,521
Revolving Loans Converted to Term | 6,586 | 7,810
Total | 77,528 | 78,331
Residential Real Estate Lines [Member] | Non-Performing [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 0 | 0
Prior Fiscal Year 1 | 0 | 0
Prior Fiscal Year 2 | 0 | 0
Prior Fiscal Year 3 | 0 | 0
Prior Fiscal Year 4 | 0 | 0
Prior | 0 | 0
Revolving Loans Amortized Cost Basis | 34 | 39
Revolving Loans Converted to Term | 108 | 161
Total | 142 | 200
Consumer Indirect [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 441,080 | 453,018
Prior Fiscal Year 1 | 333,111 | 206,987
Prior Fiscal Year 2 | 127,096 | 123,285
Prior Fiscal Year 3 | 60,362 | 91,228
Prior Fiscal Year 4 | 39,557 | 51,734
Prior | 22,414 | 31,796
Revolving Loans Amortized Cost Basis | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 1,023,620 | 958,048
Consumer Indirect [Member] | Performing [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 440,332 | 452,601
Prior Fiscal Year 1 | 331,902 | 206,472
Prior Fiscal Year 2 | 126,664 | 122,849
Prior Fiscal Year 3 | 59,981 | 90,998
Prior Fiscal Year 4 | 39,352 | 51,598
Prior | 22,310 | 31,750
Revolving Loans Amortized Cost Basis | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 1,020,541 | 956,268
Consumer Indirect [Member] | Non-Performing [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 748 | 417
Prior Fiscal Year 1 | 1,209 | 515
Prior Fiscal Year 2 | 432 | 436
Prior Fiscal Year 3 | 381 | 230
Prior Fiscal Year 4 | 205 | 136
Prior | 104 | 46
Revolving Loans Amortized Cost Basis | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 3,079 | 1,780
Other Consumer [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 6,463 | 4,422
Prior Fiscal Year 1 | 2,664 | 3,738
Prior Fiscal Year 2 | 2,043 | 1,681
Prior Fiscal Year 3 | 761 | 763
Prior Fiscal Year 4 | 213 | 280
Prior | 308 | 1,044
Revolving Loans Amortized Cost Basis | 2,658 | 2,549
Revolving Loans Converted to Term | 0 | 0
Total | 15,110 | 14,477
Other Consumer [Member] | Performing [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 6,463 | 4,422
Prior Fiscal Year 1 | 2,664 | 3,738
Prior Fiscal Year 2 | 2,043 | 1,681
Prior Fiscal Year 3 | 761 | 763
Prior Fiscal Year 4 | 213 | 280
Prior | 308 | 1,044
Revolving Loans Amortized Cost Basis | 2,656 | 2,549
Revolving Loans Converted to Term | 0 | 0
Total | 15,108 | 14,477
Other Consumer [Member] | Non-Performing [Member] |  |
Financing Receivable Recorded Investment [Line Items] |  |
Current Fiscal Year | 0 | 0
Prior Fiscal Year 1 | 0 | 0
Prior Fiscal Year 2 | 0 | 0
Prior Fiscal Year 3 | 0 | 0
Prior Fiscal Year 4 | 0 | 0
Prior | 0 | 0
Revolving Loans Amortized Cost Basis | 2 | 0
Revolving Loans Converted to Term | 0 | 0
Total | $ 2 | $ 0

X
- Definition Financing receivable after deferred income offset amount. + References No definition available. + Details
Name: | fisi_FinancingReceivableAfterDeferredIncomeOffsetAmount
Namespace Prefix: | fisi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivable (payable) originated five or more years before latest fiscal year. + References No definition available. + Details
Name: | fisi_FinancingReceivablePayableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear
Namespace Prefix: | fisi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated in current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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
Name: | us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortized cost of financing receivable that can be withdrawn, repaid, and redrawn. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableRevolving
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of revolving financing receivable converted to term loan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6A -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120270059-210447 + Details
Name: | us-gaap_FinancingReceivableRevolvingConvertedToTermLoan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fisi_ConsumerIndirectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |