Note 12 - Lease Obligations - Future Minimum Annual Lease Commitments (Details) $ in Thousands	Mar. 31, 2024 USD ($)
2025	$ 96
Lessee, Operating Lease, Minimum Lease Commitments, to be Paid	$ 96

Amount of minimum lease commitments for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

No definition available.

Name:	bdco_LesseeOperatingLeaseMinimumLeaseCommitmentsToBePaidYearOne
Namespace Prefix:	bdco_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant