Name:	kffb_ScheduleOfDepositsAbstract
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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

Name:	us-gaap_Deposits
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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.

Name:	us-gaap_DepositsMoneyMarketDeposits
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Period Type:	instant

Amount of interest-bearing domestic checking deposit liabilities.

Name:	us-gaap_InterestBearingDomesticDepositChecking
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Data Type:	xbrli:monetaryItemType
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Amount of interest-bearing domestic savings deposit liabilities. Saving deposits bear interest and have no stated maturity.

Name:	us-gaap_InterestBearingDomesticDepositSavings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of domestic noninterest-bearing deposits held by the entity, which may include demand deposits, checking, brokered and retail deposits.

Name:	us-gaap_NoninterestBearingDepositLiabilitiesDomestic
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Amount of noninterest-bearing domestic checking deposit liabilities.