Note 4 - Discontinued Operations (Details Textual) - Crude Oil Pipeline Services [Member] - Discontinued Operations, Held-for-sale [Member] $ in Millions	3 Months Ended
Mar. 31, 2022 USD ($)
Proceeds from Divestiture of Businesses, Held in Escrow	$ 1.2
Exit and Disposal Costs	$ 1.9

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period, which is currently held in escrow.

No definition available.

Name:	bkep_ProceedsFromDivestitureOfBusinessesHeldInEscrow
Namespace Prefix:	bkep_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant