XML 41 R31.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Loans Receivable (Details) - Schedule of TDR loan modifications - Chapter 7 bankruptcy [Member] - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Residential real estate: |  |
Troubled debt restructurings | $ 144 | $ 144
Troubled Debt Restructurings Performing to Modified Terms [Member] |  |
Residential real estate: |  |
Troubled debt restructurings | 144 | 144
Troubled Debt Restructurings Not Performing to Modified Terms [Member] |  |
Residential real estate: |  |
Troubled debt restructurings |  |

X
- References No definition available. + Details
Name: | kffb_ResidentialRealEstateAbstract00000000000
Namespace Prefix: | kffb_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.13) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_PropertyPlantAndEquipmentGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_CollateralAxis=kffb_Chapter7BankruptcyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=kffb_TroubledDebtRestructuringsPerformingToModifiedTermsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=kffb_TroubledDebtRestructuringsNotPerformingToModifiedTermsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |