Percentage of annual increase of annual rental, maintenance, and tax expenses attributable to operating leases.

No definition available.

Name:	bkti_LesseeOperatingLeaseAnnualPercentageIncreaseInRentalMaintenanceAndTaxExpenses
Namespace Prefix:	bkti_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of annual rental, maintenance, and tax expenses attributable to operating leases.

+ References

No definition available.

+ Details

Name:	bkti_LesseeOperatingLeaseAnnualRentalMaintenanceAndTaxExpense
Namespace Prefix:	bkti_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Area of a real estate property.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 970
-SubTopic 360
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-28(Column A)(Footnote 2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478979/970-360-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 970
-SubTopic 360
-Name Accounting Standards Codification
-Section 30
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478150/970-360-30-2

+ Details

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_LeaseContractualTermAxis=bkti_IndustrialSpaceInWestMelbourneFloridaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseContractualTermAxis=bkti_OfficeSpaceAtSawgrassTechnologyParkMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 8 - Leases (Details Textual) $ in Thousands	3 Months Ended
Note 8 - Leases (Details Textual) $ in Thousands	Mar. 31, 2026 USD ($) ft²	Feb. 01, 2026 ft²	Jan. 01, 2026	Sep. 24, 2025 ft²	Feb. 29, 2020 ft²
Industrial Space in West Melbourne, Florida [Member]
Area of Real Estate Property (Square Foot) \| ft²	54,000	31,500
Lessee, Operating Lease, Renewal Term (Year)	5 years		5 years
Lessee, Operating Lease, Annual Rental, Maintenance, and Tax Expense \| $	$ 610
Lessee, Operating Lease, Term of Contract (Month)		125 months
Office Space at Sawgrass Technology Park [Member]
Area of Real Estate Property (Square Foot) \| ft²				1,514	6,857
Lessee, Operating Lease, Annual Rental, Maintenance, and Tax Expense \| $	$ 180
Lessee, Operating Lease, Term of Contract (Month)					64 months
Lessee, Operating Lease, Annual Percentage Increase in Rental, Maintenance, and Tax Expenses	3.00%