XML 74 R65.htm IDEA: XBRL DOCUMENT
v3.23.3

Fair Value (Carrying amount and estimated fair value of financial instruments) (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
LIABILITIES |  |  |
Federal Funds Purchased and Securities Sold under Agreements to Repurchase |  | $ 52,330 | $ 57,771
Level 1 [Member] |  |  |
ASSETS |  |  |
Cash and cash equivalents |  | 115,879 | 38,924
Mortgage loans AFS |  | 0 | 0
Total loans |  | 0 | 0
Less allowance for loan losses |  | 0 | 0
Net loans |  | 0 | 0
Accrued interest receivable |  | 7,346 | 7,472
Equity securities without readily determinable fair values | [1] | 0 | 0
Originated mortgage servicing rights |  | 0 | 0
LIABILITIES |  |  |
Deposits without stated maturities |  | 1,437,396 | 1,492,235
Deposits with stated maturities |  | 0 | 0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase |  | 0 | 0
Federal Home Loan Bank Borrowings, Fair Value Disclosure |  | 0 |
Subordinated Debt Obligations, Fair Value Disclosure |  | 0 | 0
Accrued interest payable |  | 813 | 255
Level 2 [Member] |  |  |
ASSETS |  |  |
Cash and cash equivalents |  | 0 | 0
Mortgage loans AFS |  | 105 | 395
Total loans |  | 0 | 0
Less allowance for loan losses |  | 0 | 0
Net loans |  | 0 | 0
Accrued interest receivable |  | 0 | 0
Equity securities without readily determinable fair values | [1] | 0 | 0
Originated mortgage servicing rights |  | 3,223 | 3,174
LIABILITIES |  |  |
Deposits without stated maturities |  | 0 | 0
Deposits with stated maturities |  | 324,936 | 240,964
Federal Funds Purchased and Securities Sold under Agreements to Repurchase |  | 52,197 | 57,581
Federal Home Loan Bank Borrowings, Fair Value Disclosure |  | 65,003 |
Subordinated Debt Obligations, Fair Value Disclosure |  | 24,184 | 26,365
Accrued interest payable |  | 0 | 0
Level 3 [Member] |  |  |
ASSETS |  |  |
Cash and cash equivalents |  | 0 | 0
Mortgage loans AFS |  | 0 | 0
Total loans |  | 1,279,671 | 1,225,669
Less allowance for loan losses |  | 12,767 | 9,850
Net loans |  | 1,266,904 | 1,215,819
Accrued interest receivable |  | 0 | 0
Equity securities without readily determinable fair values | [1] | 0 | 0
Originated mortgage servicing rights |  | 0 | 0
LIABILITIES |  |  |
Deposits without stated maturities |  | 0 | 0
Deposits with stated maturities |  | 0 | 0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase |  | 0 | 0
Federal Home Loan Bank Borrowings, Fair Value Disclosure |  | 0 |
Subordinated Debt Obligations, Fair Value Disclosure |  | 0 | 0
Accrued interest payable |  | 0 | 0
Carrying Value [Member] |  |  |
ASSETS |  |  |
Cash and cash equivalents |  | 115,879 | 38,924
Mortgage loans AFS |  | 105 | 379
Total loans |  | 1,334,674 | 1,264,173
Less allowance for loan losses |  | 12,767 | 9,850
Net loans |  | 1,321,907 | 1,254,323
Accrued interest receivable |  | 7,346 | 7,472
Equity securities without readily determinable fair values | [1] | 15,848 | 15,746
Originated mortgage servicing rights |  | 2,463 | 2,559
LIABILITIES |  |  |
Deposits without stated maturities |  | 1,437,396 | 1,492,235
Deposits with stated maturities |  | 332,078 | 252,040
Federal Funds Purchased and Securities Sold under Agreements to Repurchase |  | 52,330 | 57,771
Federal Home Loan Bank Borrowings, Fair Value Disclosure |  | 65,000 |
Subordinated Debt Obligations, Fair Value Disclosure |  | 29,312 | 29,245
Accrued interest payable |  | 813 | 255
Estimated Fair Value [Member] |  |  |
ASSETS |  |  |
Cash and cash equivalents |  | 115,879 | 38,924
Mortgage loans AFS |  | 105 | 395
Total loans |  | 1,279,671 | 1,225,669
Less allowance for loan losses |  | 12,767 | 9,850
Net loans |  | 1,266,904 | 1,215,819
Accrued interest receivable |  | 7,346 | 7,472
Originated mortgage servicing rights |  | 3,223 | 3,174
LIABILITIES |  |  |
Deposits without stated maturities |  | 1,437,396 | 1,492,235
Deposits with stated maturities |  | 324,936 | 240,964
Federal Funds Purchased and Securities Sold under Agreements to Repurchase |  | 52,197 | 57,581
Federal Home Loan Bank Borrowings, Fair Value Disclosure |  | 65,003 |
Subordinated Debt Obligations, Fair Value Disclosure |  | 24,184 | 26,365
Accrued interest payable |  | $ 813 | $ 255
[1] | Due to the characteristics of equity securities without readily determinable fair values, they are not disclosed under a specific fair value hierarchy. When an impairment or write-down related to these securities is recorded, such amount would be classified as a nonrecurring Level 3 fair value adjustment.

X
- Definition Deposits With Stated Maturities, Fair Value Disclosure + References No definition available. + Details
Name: | isba_DepositsWithStatedMaturitiesFairValueDisclosure
Namespace Prefix: | isba_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Deposits Without Stated Maturities, Fair Value Disclosure + References No definition available. + Details
Name: | isba_DepositsWithoutStatedMaturitiesFairValueDisclosure
Namespace Prefix: | isba_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Equity Method And Other Investments, Fair Value Disclosure + References No definition available. + Details
Name: | isba_EquityMethodAndOtherInvestmentsFairValueDisclosure
Namespace Prefix: | isba_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Interest Payable, Fair Value Disclosure + References No definition available. + Details
Name: | isba_InterestPayableFairValueDisclosure
Namespace Prefix: | isba_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Interest Receivable, Fair Value Disclosure + References No definition available. + Details
Name: | isba_InterestReceivableFairValueDisclosure
Namespace Prefix: | isba_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Loans Receivable, Allowance, Fair Value Disclosure + References No definition available. + Details
Name: | isba_LoansReceivableAllowanceFairValueDisclosure
Namespace Prefix: | isba_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Loans Receivable, Gross, Fair Value Disclosure + References No definition available. + Details
Name: | isba_LoansReceivableGrossFairValueDisclosure
Namespace Prefix: | isba_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References No definition available. + Details
Name: | us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount after offset of short term borrowing where a bank borrows, at the federal funds rate, from another bank and securities that an entity sells and agrees to repurchase at a specified date for a specified price. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 + Details
Name: | us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of borrowing from Federal Home Loan Bank (FHLBank). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13(3)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 + Details
Name: | us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Publisher FASB -URI https://asc.fasb.org//310-10/tableOfContent + Details
Name: | us-gaap_LoansReceivableFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of mortgage loans held-for-sale. + References No definition available. + Details
Name: | us-gaap_MortgagesHeldForSaleFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481229/860-50-50-3 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481260/860-50-45-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481260/860-50-45-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481260/860-50-45-2 + Details
Name: | us-gaap_ServicingAssetAtFairValueAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |