XML 115 R105.htm IDEA: XBRL DOCUMENT
v3.23.2

Disclosures about Fair Value of Assets - Quantitative Information about Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements (Detail) | 12 Months Ended
--- | ---
Jun. 30, 2023 USD ($) yr mo | Jun. 30, 2022 USD ($) mo yr
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights | $ 1,482,000 | $ 1,463,000
Impaired loans (collateral dependent) | $ 2,361,000 | $ 2,662,000
Discount Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 9.5 | 9.5
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 | 6 | 6
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 | 0.09 | 0.1
Minimum [Member] | Maturity/Call Date [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | mo | 1 | 1
Minimum [Member] | Weighted average coupon [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 2.97 | 2.97
Minimum [Member] | Marketability yield adjustment [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 1 | 1
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 | 7 | 6.7
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 | 0.12 | 0.14
Maximum [Member] | Maturity/Call Date [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | yr | 9 | 10
Maximum [Member] | Weighted average coupon [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 3.08 | 3.08
Maximum [Member] | Marketability yield adjustment [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 2 | 2
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 | 9.5 | 9.5
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 | 6.9 | 6.7
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 | 0.12 | 0.12
Weighted Average [Member] | Weighted average coupon [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 3.04 | 3.03
Weighted Average [Member] | Marketability yield adjustment [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 1.6 | 1.6

X
- Definition Impaired loans gain losses recognized on assets fair value disclosure. + References No definition available. + Details
Name: | iroq_ImpairedLoansGainLossesRecognizedOnAssetsFairValueDisclosure
Namespace Prefix: | iroq_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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: | 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: | srt_RangeAxis=srt_MinimumMember
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: | us-gaap_MeasurementInputTypeAxis=iroq_MaturityCallDateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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