Note 1 - Organization (Details Textual) $ / shares in Units, $ in Thousands			1 Months Ended	3 Months Ended		12 Months Ended	15 Months Ended	24 Months Ended
		May 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Mar. 31, 2024 USD ($) $ / shares bbl	Mar. 31, 2023 USD ($) $ / shares	Dec. 31, 2023 USD ($)	Mar. 31, 2024 USD ($) bbl	Apr. 30, 2027 USD ($)
Distillation Tower, Volume Per Day (Barrel of Oil) | bbl				15,000			15,000
Volume of Storage Tank Capacity (Barrel of Oil) | bbl				1,250,000			1,250,000
Number of Operating Segments							2
Working Capital (Deficit)				$ 300		$ (6,100)	$ 300
Working Capital (Deficit), Change From Previous Reporting Period				6,400
Secured Debt, Current				40,600		39,400	40,600
Secured Debt, Current, Change From Previous Reporting Period				1,100
Assets, Current				52,838		49,290	52,838
Assets, Current, Change From Previous Reporting Period				3,500
Liabilities, Current				52,535		55,425	52,535
Liabilities, Current, Change From Previous Reporting Period				2,900
Liabilities, Other than Current Portion of Long-Term Debt, Current				12,000		16,000	12,000
Liabilities, Other than Current Portion of Long-Term Debt, Current, Change From Previous Reporting Period				4,000
Repayments of Long-Term Debt				345	$ 560
Net Income (Loss) Attributable to Parent				$ 6,624	$ 16,753
Earnings Per Share, Basic (in dollars per share) | $ / shares				$ 0.44	$ 1.12
Net Income (Loss), Change From Previous Reporting Period				$ 10,100
Earnings Per Share Basic, Change From Previous Reporting Period (in dollars per share) | $ / shares				$ 0.68
Working Capital (Deficit), Excluding Long-term Debt, Current				$ 40,900		33,300	$ 40,900
Working Capital (Deficit), Excluding Current Portion of Long-term Debt, Change From Previous Reporting Period				$ 7,600
An Affiliate Combined with Jonathan Carroll [Member]
Ownership Percentage				83.00%			83.00%
Nonrelated Party [Member]
Debt Instrument, Periodic Payment	[1]			$ 10
Nonrelated Party [Member] | Veritex Community Bank [Member]
Repayments of Long-Term Debt				4,300
Escrow Deposit				1,000			$ 1,000
Legal Fees				40
Nonrelated Party [Member] | Kissick Forbearance Agreement [Member]
Debt Instrument, Periodic Payment			$ 500	500
Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid				400		400	$ 400
Repayments of Notes Payable				1,500	$ 0
Nonrelated Party [Member] | LEH Forbearance Agreement [Member]
Debt Instrument, Periodic Payment		$ 50				$ 50
Repayments of Notes Payable				$ 100	$ 0
Nonrelated Party [Member] | LEH Forbearance Agreement [Member] | Forecast [Member]
Debt Instrument, Periodic Payment								$ 400

[1] Original principal amount was $0.5 million; the Blue Dolphin Term Loan Due 2051 was modified to increase the principal amount by $1.5 million. Payments deferred for thirty (30) months; first payment due and paid in November 2023; interest accrues during deferral period; loan not forgivable.