XML 59 R50.htm IDEA: XBRL DOCUMENT
v3.23.3

Loans and ACL (Summary of changes in ACL by segments) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2022
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Beginning Balance | $ 12,833 | $ 9,700 | $ 9,850 | $ 9,103 |
Allowance for loan losses, Charge-offs | (179) | (173) | (372) | (370) |
Allowance for loan losses, Recoveries | 433 | 132 | 638 | 404 |
Financing Receivable, Credit Loss, Expense (Reversal) | (320) | 18 | (93) | 540 |
Allowance for loan losses, Ending Balance | 12,767 | 9,677 | 12,767 | 9,677 |
Individually evaluated for impairment, ACL |  |  |  |  | $ 451
Collectively evaluated for impairment, ALLL |  |  |  |  | 9,399
Financing Receivable, Individually Evaluated for Impairment |  |  |  |  | 22,018
Financing Receivable, Collectively Evaluated for Impairment |  |  |  |  | 1,242,155
Total |  |  |  |  | 1,264,173
Accounting Standards Update 2016-13 |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Ending Balance | 2,744 |  | 2,744 |  |
Commercial [Member] |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Beginning Balance | 822 |  | 860 |  |
Allowance for loan losses, Charge-offs | (29) |  | (29) |  |
Allowance for loan losses, Recoveries | 70 |  | 74 |  |
Financing Receivable, Credit Loss, Expense (Reversal) | (34) |  | (18) |  |
Allowance for loan losses, Ending Balance | 829 |  | 829 |  |
Total |  |  |  |  | 744,440
Commercial [Member] | Accounting Standards Update 2016-13 |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Ending Balance | (58) |  | (58) |  |
Commercial Real Estate |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Beginning Balance | 5,968 |  | 461 |  |
Allowance for loan losses, Charge-offs | 0 |  | 0 |  |
Allowance for loan losses, Recoveries | 3 |  | 23 |  |
Financing Receivable, Credit Loss, Expense (Reversal) | (101) |  | (146) |  |
Allowance for loan losses, Ending Balance | 5,870 |  | 5,870 |  |
Commercial Real Estate | Accounting Standards Update 2016-13 |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Ending Balance | 5,532 |  | 5,532 |  |
Commercial and Commercial Real Estate Portfolio Segment |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Beginning Balance |  | 1,758 | 1,321 | 1,740 |
Allowance for loan losses, Charge-offs |  | 0 |  | (3) |
Allowance for loan losses, Recoveries |  | 14 |  | 54 |
Financing Receivable, Credit Loss, Expense (Reversal) |  | (436) |  | (455) |
Allowance for loan losses, Ending Balance |  | 1,336 |  | 1,336 |
Individually evaluated for impairment, ACL |  |  |  |  | 12
Collectively evaluated for impairment, ALLL |  |  |  |  | 1,309
Financing Receivable, Individually Evaluated for Impairment |  |  |  |  | 8,342
Financing Receivable, Collectively Evaluated for Impairment |  |  |  |  | 736,098
Total |  |  |  |  | 744,440
Agricultural [Member] |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Beginning Balance | 264 | 451 | 577 | 289 |
Allowance for loan losses, Charge-offs | 0 | 0 | (4) | 0 |
Allowance for loan losses, Recoveries | 0 | 1 | 6 | 4 |
Financing Receivable, Credit Loss, Expense (Reversal) | 5 | 35 | (63) | 194 |
Allowance for loan losses, Ending Balance | 269 | 487 | 269 | 487 |
Individually evaluated for impairment, ACL |  |  |  |  | 0
Collectively evaluated for impairment, ALLL |  |  |  |  | 577
Financing Receivable, Individually Evaluated for Impairment |  |  |  |  | 10,935
Financing Receivable, Collectively Evaluated for Impairment |  |  |  |  | 94,050
Total |  |  |  |  | 104,985
Agricultural [Member] | Accounting Standards Update 2016-13 |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Ending Balance | (247) |  | (247) |  |
Residential Mortgage |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Beginning Balance | 4,173 | 639 | 617 | 747 |
Allowance for loan losses, Charge-offs | 0 | 0 | (2) | 0 |
Allowance for loan losses, Recoveries | 266 | 53 | 315 | 123 |
Financing Receivable, Credit Loss, Expense (Reversal) | (281) | (70) | (307) | (248) |
Allowance for loan losses, Ending Balance | 4,158 | 622 | 4,158 | 622 |
Individually evaluated for impairment, ACL |  |  |  |  | 439
Collectively evaluated for impairment, ALLL |  |  |  |  | 178
Financing Receivable, Individually Evaluated for Impairment |  |  |  |  | 2,741
Financing Receivable, Collectively Evaluated for Impairment |  |  |  |  | 333,953
Total |  |  |  |  | 336,694
Residential Mortgage | Accounting Standards Update 2016-13 |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Ending Balance | 3,535 |  | 3,535 |  |
Consumer Portfolio Segment [Member] |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Beginning Balance | 1,606 | 1,323 | 961 | 908 |
Allowance for loan losses, Charge-offs | (150) | (173) | (337) | (367) |
Allowance for loan losses, Recoveries | 94 | 64 | 220 | 223 |
Financing Receivable, Credit Loss, Expense (Reversal) | 91 | (168) | 441 | 282 |
Allowance for loan losses, Ending Balance | 1,641 | 1,046 | 1,641 | 1,046 |
Individually evaluated for impairment, ACL |  |  |  |  | 0
Collectively evaluated for impairment, ALLL |  |  |  |  | 961
Financing Receivable, Individually Evaluated for Impairment |  |  |  |  | 0
Financing Receivable, Collectively Evaluated for Impairment |  |  |  |  | 78,054
Total |  |  |  |  | 78,054
Consumer Portfolio Segment [Member] | Accounting Standards Update 2016-13 |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Ending Balance | 356 |  | 356 |  |
Unallocated [Member] |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Beginning Balance | 0 | 5,529 | 6,374 | 5,419 |
Allowance for loan losses, Charge-offs | 0 | 0 | 0 | 0 |
Allowance for loan losses, Recoveries | 0 | 0 | 0 | 0 |
Financing Receivable, Credit Loss, Expense (Reversal) | 0 | 657 | 0 | 767 |
Allowance for loan losses, Ending Balance | 0 | $ 6,186 | 0 | $ 6,186 |
Individually evaluated for impairment, ACL |  |  |  |  | 0
Collectively evaluated for impairment, ALLL |  |  |  |  | $ 6,374
Unallocated [Member] | Accounting Standards Update 2016-13 |  |  |  |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |  |  |  |
Allowance for loan losses, Ending Balance | $ (6,374) |  | $ (6,374) |  |

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_AllowanceForLoanAndLeaseLossesRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (1) -Publisher SEC Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (3) -Publisher SEC Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (c) -Publisher SEC Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(7)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 11B -Subparagraph (c)(1) -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 11B -Subparagraph (g) -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 11B -Subparagraph (g) -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of increase in allowance for credit loss on financing receivable from recovery. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 11B -Subparagraph (c)(4) -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of writeoff of financing receivable, charged against allowance for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 11B -Subparagraph (c)(3) -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The balance of financing receivables that were collectively evaluated for impairment. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 6.L(5)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480418/310-10-S99-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11C -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11C + Details
Name: | us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The balance of financing receivables that were individually evaluated for impairment. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11C -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11C Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 6.L(5)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480418/310-10-S99-4 + Details
Name: | us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 80 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479294/326-20-55-80 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479294/326-20-55-79 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (1) -Publisher SEC Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (2) -Publisher SEC Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Name Regulation S-K (SK) -Number 229 -Section 1404 -Paragraph (a) -Publisher SEC Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-14 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 7A -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-7A Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_NotesReceivableGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of credit loss expense (reversal of expense) for financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(11)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 + Details
Name: | us-gaap_ProvisionForLoanLossesExpensed
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_CumulativeEffectPeriodOfAdoptionAxis=us-gaap_AccountingStandardsUpdate201613Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember
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: |

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