v3.25.4

Note 13 - Significant Customers (Details Textual) Pure in Thousands	12 Months Ended
	Dec. 31, 2025
Customer Concentration Risk [Member] \| Accounts Receivable [Member]
Number of Customers	0

Represents the number of customers during the period.

No definition available.

Name:	bkti_NumberOfCustomers
Namespace Prefix:	bkti_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: