Employee Stock Ownership Plan (ESOP) - Summary of ESOP Shares (Parenthetical) (Detail) (USD $)	6 Months Ended	12 Months Ended
Dec. 31, 2012	Jun. 30, 2012
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
ESOP, closing price per share	$ 13.80	$ 13.24

Closing price of share to calculate unearned ESOP shares.

No definition available.

Name:	iroq_ClosingPriceOfShareToCalculateUnearnedEsopShares
Namespace Prefix:	iroq_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration