XML 70 R60.htm IDEA: XBRL DOCUMENT
v3.21.2

Disclosures about Fair Value of Assets - Quantitative Information about Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements (Detail) Banking_Office in Thousands, $ in Thousands | Sep. 30, 2021 USD ($) | Jun. 30, 2021 USD ($) Banking_Office
--- | --- | ---
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights | $ | $ 1,020 | $ 1,013
Foreclosed assets | Banking_Office |  | 191
Minimum [Member] | Discount Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.095 | 0.095
Minimum [Member] | Constant Prepayment Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.104 | 0.098
Minimum [Member] | Probability of Default [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.0000 | 0.0000
Maximum [Member] | Discount Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.116 | 0.115
Maximum [Member] | Constant Prepayment Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.147 | 0.144
Maximum [Member] | Probability of Default [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.0014 | 0.0014
Maximum [Member] | Comparability Adjustments [Member] | Market Comparable Properties [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input |  | 0.116
Weighted Average [Member] | Discount Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.095 | 0.095
Weighted Average [Member] | Constant Prepayment Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.125 | 0.119
Weighted Average [Member] | Probability of Default [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.0012 | 0.0012
Weighted Average [Member] | Comparability Adjustments [Member] | Market Comparable Properties [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input |  | 0.116

X
- Definition Foreclosed assets measurement input. + References No definition available. + Details
Name: | iroq_ForeclosedAssetsMeasurementInput
Namespace Prefix: | iroq_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Mortgage servicing rights fair value disclosure. + References No definition available. + Details
Name: | iroq_MortgageServicingRightsFairValueDisclosure
Namespace Prefix: | iroq_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Mortgage servicing rights measurement input. + References No definition available. + Details
Name: | iroq_MortgageServicingRightsMeasurementInput
Namespace Prefix: | iroq_
Data Type: | xbrli:decimalItemType
Balance Type: | na
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_FairValueOffBalanceSheetRisksDisclosureInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDiscountRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_ValuationTechniqueDiscountedCashFlowMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputConstantPrepaymentRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDefaultRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputComparabilityAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=iroq_MarketComparablePropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |