XML 57 R48.htm IDEA: XBRL DOCUMENT
v3.23.3

Loans and Allowance for Credit Losses - Allowance for Credit Losses (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Jun. 30, 2023
Allowance for loan losses: |  |  |
Balance, beginning of year | $ 7,139 | $ 7,052 | $ 7,052
Impact of adopting ASU 2016-13 |  | 47 | 47
Provision charged to expense | 310 | (67) | 52
Losses charged off | (7) | (16) | (51)
Recoveries | 8 | 7 | 39
Balance, end of period | 7,450 | 7,023 | 7,139
Loans: |  |  |
Ending balance | 621,771 | 550,905 | 594,324
One- to four-family [Member] |  |  |
Allowance for loan losses: |  |  |
Balance, beginning of year | 1,898 | 1,028 | 1,028
Impact of adopting ASU 2016-13 |  | 382 | 382
Provision charged to expense | 8 | 126 | 487
Losses charged off | 0 | 0 | 0
Recoveries | 0 | 1 | 1
Balance, end of period | 1,906 | 1,537 | 1,898
Loans: |  |  |
Ending balance | 170,154 | 142,417 | 163,854
Multi-family [Member] |  |  |
Allowance for loan losses: |  |  |
Balance, beginning of year | 1,121 | 1,375 | 1,375
Impact of adopting ASU 2016-13 |  | (140) | (140)
Provision charged to expense | (6) | 49 | (114)
Losses charged off | 0 | 0 | 0
Recoveries | 0 | 0 | 0
Balance, end of period | 1,115 | 1,284 | 1,121
Loans: |  |  |
Ending balance | 89,177 | 98,778 | 89,649
Home equity lines of credit [Member] |  |  |
Allowance for loan losses: |  |  |
Balance, beginning of year | 121 | 70 | 70
Impact of adopting ASU 2016-13 |  | 33 | 33
Provision charged to expense | 13 | (9) | 18
Losses charged off | 0 | 0 | 0
Recoveries | 0 | 0 | 0
Balance, end of period | 134 | 94 | 121
Loans: |  |  |
Ending balance | 8,511 | 6,778 | 8,066
Construction [Member] |  |  |
Allowance for loan losses: |  |  |
Balance, beginning of year | 765 | 489 | 489
Impact of adopting ASU 2016-13 |  | 192 | 192
Provision charged to expense | 400 | (132) | 84
Losses charged off | 0 | 0 | 0
Recoveries | 0 | 0 | 0
Balance, end of period | 1,165 | 549 | 765
Loans: |  |  |
Ending balance | 72,810 | 34,314 | 50,973
Commercial [Member] |  |  |
Allowance for loan losses: |  |  |
Balance, beginning of year | 2,369 | 1,985 | 1,985
Impact of adopting ASU 2016-13 |  | 385 | 385
Provision charged to expense | (104) | 16 | (1)
Losses charged off | 0 | 0 | 0
Recoveries | 0 | 0 | 0
Balance, end of period | 2,265 | 2,386 | 2,369
Loans: |  |  |
Ending balance | 193,582 | 181,934 | 193,707
Commercial [Member] |  |  |
Allowance for loan losses: |  |  |
Balance, beginning of year | 794 | 2,025 | 2,025
Impact of adopting ASU 2016-13 |  | (818) | (818)
Provision charged to expense | (12) | (117) | (422)
Losses charged off | 0 | (4) | (14)
Recoveries | 6 | 4 | 23
Balance, end of period | 788 | 1,090 | 794
Loans: |  |  |
Ending balance | 79,194 | 77,103 | 79,693
Consumer [Member] |  |  |
Allowance for loan losses: |  |  |
Balance, beginning of year | 71 | 80 | 80
Impact of adopting ASU 2016-13 |  | 13 | 13
Provision charged to expense | 11 | 0 | 0
Losses charged off | (7) | (12) | (37)
Recoveries | 2 | 2 | 15
Balance, end of period | 77 | 83 | 71
Loans: |  |  |
Ending balance | $ 8,343 | $ 9,581 | $ 8,382

X
- Definition Allowance for loan losses. + References No definition available. + Details
Name: | iroq_AllowanceForLoanLossesAbstract
Namespace Prefix: | iroq_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Impact of adopting ASU 2016-13. + References No definition available. + Details
Name: | iroq_ImpactOfAdoptingASU201613
Namespace Prefix: | iroq_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Loans. + References No definition available. + Details
Name: | iroq_LoansAbstract
Namespace Prefix: | iroq_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase (decrease) of allowance reserve for credit loss. + References No definition available. + Details
Name: | us-gaap_AllowanceForLoanAndLeaseLossesPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

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 Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b)(1)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481696/310-30-50-2 Reference 2: 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 3: 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 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 6.L.1) -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480418/310-10-S99-4 + Details
Name: | us-gaap_LoansAndLeasesReceivableAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481990/310-10-45-2 + Details
Name: | us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

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

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

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |