Cash donation.

No definition available.

Name:	iroq_CashDonation
Namespace Prefix:	iroq_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of donated shares of common stock.

+ References

No definition available.

+ Details

Name:	iroq_NumberOfDonatedSharesOfCommonStock
Namespace Prefix:	iroq_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Organization and basis of presentation.

+ References

No definition available.

+ Details

Name:	iroq_OrganizationAndBasisOfPresentationLineItems
Namespace Prefix:	iroq_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from the additional capital contribution to the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_IPOMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_EmployeeStockOwnershipPlanESOPDisclosuresByPlanAxis=iroq_EmployeeStockOwnershipPlanEsopMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=iroq_IroquoisFederalFoundationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Basis of Financial Statement Presentation - Additional Information (Detail) - USD ($)	Jul. 07, 2011	Dec. 31, 2019	Jun. 30, 2019
Organization and Basis of Presentation [Line Items]
Common stock, shares issued		3,263,171	3,578,252
IPO [Member]
Organization and Basis of Presentation [Line Items]
Common stock, shares issued	4,496,500
Sale of stock price per share	$ 10.00
Proceeds from sale of common stock	$ 45,000,000
Employee Stock Ownership Plan Esop [Member] \| IPO [Member]
Organization and Basis of Presentation [Line Items]
Common stock, shares issued	384,900
Iroquois Federal Foundation [Member]
Organization and Basis of Presentation [Line Items]
Number of donated shares of common stock	314,755
Cash contributed to the foundation	$ 450,000