XML 54 R44.htm IDEA: XBRL DOCUMENT
v3.20.2

Loans and ALLL (Past due and current loans) (Details) - USD ($) $ in Thousands | Sep. 30, 2020 | Dec. 31, 2019
--- | --- | ---
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | $ 0 | $ 0
Nonaccrual | 4,946 | 6,535
Total Past Due and Nonaccrual | 7,217 | 11,405
Current | 1,296,091 | 1,175,165
Total | 1,303,308 | 1,186,570
Total commercial [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 1,364 | 1,621
Total Past Due and Nonaccrual | 2,082 | 2,477
Current | 819,020 | 698,464
Total | 821,102 | 700,941
Commercial real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 27 | 390
Total Past Due and Nonaccrual | 178 | 559
Current | 499,208 | 509,594
Total | 499,386 | 510,153
Commercial other [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 1,337 | 1,231
Total Past Due and Nonaccrual | 1,904 | 1,918
Current | 244,796 | 153,347
Total | 246,700 | 155,265
Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 0 | 0
Total Past Due and Nonaccrual | 0 | 0
Current | 75,016 | 35,523
Total | 75,016 | 35,523
Total agricultural [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 3,538 | 4,285
Total Past Due and Nonaccrual | 3,903 | 4,285
Current | 98,360 | 112,635
Total | 102,263 | 116,920
Agricultural real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 3,101 | 2,711
Total Past Due and Nonaccrual | 3,466 | 2,711
Current | 68,473 | 77,316
Total | 71,939 | 80,027
Agricultural other [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 437 | 1,574
Total Past Due and Nonaccrual | 437 | 1,574
Current | 29,887 | 35,319
Total | 30,324 | 36,893
Total residential real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 44 | 629
Total Past Due and Nonaccrual | 1,160 | 4,572
Current | 303,399 | 293,997
Total | 304,559 | 298,569
Residential real estate senior liens [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 44 | 557
Total Past Due and Nonaccrual | 1,143 | 4,278
Current | 267,160 | 253,894
Total | 268,303 | 258,172
Residential real estate junior liens [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 0 | 0
Total Past Due and Nonaccrual | 17 | 65
Current | 4,249 | 5,766
Total | 4,266 | 5,831
Residential real estate home equity lines of credit [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 0 | 72
Total Past Due and Nonaccrual | 0 | 229
Current | 31,990 | 34,337
Total | 31,990 | 34,566
Total Consumer [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 0 | 0
Total Past Due and Nonaccrual | 72 | 71
Current | 75,312 | 70,069
Total | 75,384 | 70,140
Consumer secured [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 0 | 0
Total Past Due and Nonaccrual | 68 | 68
Current | 71,762 | 66,547
Total | 71,830 | 66,615
Consumer Unsecured Financing Receivable [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, 90 Days or More Past Due, Still Accruing | 0 | 0
Nonaccrual | 0 | 0
Total Past Due and Nonaccrual | 4 | 3
Current | 3,550 | 3,522
Total | 3,554 | 3,525
Financial Asset, 30 to 59 Days Past Due [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 1,968 | 4,426
Financial Asset, 30 to 59 Days Past Due [Member] | Total commercial [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 718 | 670
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 151 | 139
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial other [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 567 | 531
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 0
Financial Asset, 30 to 59 Days Past Due [Member] | Total agricultural [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 270 | 0
Financial Asset, 30 to 59 Days Past Due [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 270 | 0
Financial Asset, 30 to 59 Days Past Due [Member] | Agricultural other [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 0
Financial Asset, 30 to 59 Days Past Due [Member] | Total residential real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 908 | 3,685
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate senior liens [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 891 | 3,463
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate junior liens [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 17 | 65
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate home equity lines of credit [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 157
Financial Asset, 30 to 59 Days Past Due [Member] | Total Consumer [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 72 | 71
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer secured [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 68 | 68
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Unsecured Financing Receivable [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 4 | 3
Financial Asset, 60 to 89 Days Past Due [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 303 | 444
Financial Asset, 60 to 89 Days Past Due [Member] | Total commercial [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 186
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 30
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial other [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 156
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 0
Financial Asset, 60 to 89 Days Past Due [Member] | Total agricultural [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 95 | 0
Financial Asset, 60 to 89 Days Past Due [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 95 | 0
Financial Asset, 60 to 89 Days Past Due [Member] | Agricultural other [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 0
Financial Asset, 60 to 89 Days Past Due [Member] | Total residential real estate [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 208 | 258
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate senior liens [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 208 | 258
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate junior liens [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 0
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate home equity lines of credit [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 0
Financial Asset, 60 to 89 Days Past Due [Member] | Total Consumer [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer secured [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | 0 | 0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Unsecured Financing Receivable [Member] |  |
Financing Receivable, Past Due [Line Items] |  |
Financing Receivable, Past Due | $ 0 | $ 0

X
- Definition Financing Receivable, Recorded Investment, Past Due And Nonaccrual Status + References No definition available. + Details
Name: | isba_FinancingReceivableRecordedInvestmentPastDueAndNonaccrualStatus
Namespace Prefix: | isba_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable 90 days or more past due and still accruing. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 16 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919258-210447 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5111-111524 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 80 -URI http://asc.fasb.org/extlink&oid=118955255&loc=SL82922355-210448 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable not past due. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 80 -URI http://asc.fasb.org/extlink&oid=118955255&loc=SL82922355-210448 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919253-210447 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable on nonaccrual status. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5111-111524 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 16 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919258-210447 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable past due. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 80 -URI http://asc.fasb.org/extlink&oid=118955255&loc=SL82922355-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919253-210447 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentPastDue
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_FinancingReceivableRecordedInvestmentPastDueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, before allowance for credit loss, of financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919230-210447 + Details
Name: | us-gaap_NotesReceivableGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

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

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

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

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |