Name:	bkyf_EffectiveIncomeTaxRateReconciliationIncentiveStockOptions
Namespace Prefix:	bkyf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of effective income tax rate reconciliation income before income tax

No definition available.

Name:	bkyf_EffectiveIncomeTaxRateReconciliationIncomeBeforeIncometax
Namespace Prefix:	bkyf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by company owned life insurance income during the period.

No definition available.

Name:	bkyf_EffectiveIncomeTaxRateReconciliationLifeInsuranceIncome
Namespace Prefix:	bkyf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by Low-income housing tax credit

No definition available.

Name:	bkyf_EffectiveIncomeTaxRateReconciliationLowIncomeHousingTaxCredit
Namespace Prefix:	bkyf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by non qualified options expired.

No definition available.

Name:	bkyf_EffectiveIncomeTaxRateReconciliationNonQualifiedOptionsExpired
Namespace Prefix:	bkyf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by Other income.

No definition available.

Name:	bkyf_EffectiveIncomeTaxRateReconciliationOtherTax
Namespace Prefix:	bkyf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6515339

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

Name:	us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income (loss) exempt from income taxes.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319