Name:	ktyb_BankServicingFeesNet
Namespace Prefix:	ktyb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The period for which the federal funds are sold generally by the entity.

No definition available.

Name:	ktyb_FederalFundsSoldPeriod
Namespace Prefix:	ktyb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the period of historical loss experience used to determine general components of allowance for loan losses.

No definition available.

Name:	ktyb_FinancingReceivableAllowanceForCreditLossesGeneralComponentsBasedOnHistoricalLossExperiencePeriod
Namespace Prefix:	ktyb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Financing receivable approved modifications due to The Coronavirus Aid, Relief and Economic Security (“CARES”) Act.

No definition available.

Name:	ktyb_FinancingReceivableApprovedModificationsDueToCoronavirusAidReliefAndEconomicSecurityCaresAct
Namespace Prefix:	ktyb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the maximum number of days past due for loans to be charged off.

No definition available.

Name:	ktyb_FinancingReceivableMaximumNumberOfDaysPastDueForLoansToBeChargedOff
Namespace Prefix:	ktyb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the maximum number of days past due for loans to be charged off due to considerations other than past due.

No definition available.

Name:	ktyb_FinancingReceivableMaximumNumberOfDaysPastDueForLoansToBeChargedOffDueToConsiderationsOtherThanPastDue
Namespace Prefix:	ktyb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the minimum number of consecutive payments made on a timely basis before returning a loan to accrual status.

No definition available.

Name:	ktyb_FinancingReceivableMinimumNumberOfConsecutivePaymentsMadeOnTimelyBasisToReturnLoansToAccrualStatus
Namespace Prefix:	ktyb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of days delinquent for discontinuation of interest income on loans.

No definition available.

Name:	ktyb_FinancingReceivableNumberOfDaysDelinquentForDiscontinuationOfInterestIncome
Namespace Prefix:	ktyb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the amount over which loans are individually evaluated for impairment.

No definition available.

Name:	ktyb_FinancingReceivableOutstandingBalanceOverWhichLoansAreIndividuallyEvaluatedForImpairment
Namespace Prefix:	ktyb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

Name:	us-gaap_AllowanceForLoanAndLeaseLossesRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (a)
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7)(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_TransfersAndServicingOfFinancialAssetsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: