Name:	kffb_DepositsExcludingTimeDeposits
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Data Type:	xbrli:monetaryItemType
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The time deposit value maturities after rolling three years.

No definition available.

Name:	kffb_TimeDepositMaturitiesAfterRollingYearThree
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Period Type:	instant

The time deposit values maturities less than rolling twelve months.

No definition available.

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Period Type:	instant

The time deposit values maturities between two and three years.

No definition available.

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Namespace Prefix:	kffb_
Data Type:	xbrli:monetaryItemType
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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.12)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 12

-Article 9

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Amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts.

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Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs).

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Amount of interest-bearing domestic checking deposit liabilities.

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- Details

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Amount of noninterest-bearing domestic checking deposit liabilities.

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Amount of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.