Loans Receivable (Details) - Schedule of Accretable Yield, or Income Expected to be Collected - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Dec. 31, 2023	Jun. 30, 2023
Schedule of Accretable Yield, or Income Expected to be Collected [Abstract]
Balance at beginning of period	$ 294	$ 339
Accretion of income	(20)	(45)
Balance at end of period	$ 274	$ 294

The aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

No definition available.

Name:	kffb_CertainLoanAcquiredInTransferAccretableYield
Namespace Prefix:	kffb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant