Note 3 - Related-party Transactions - Affiliate Long-term Debt (Details) - Related Party [Member] - Blue Dolphin Pipe Line Company (BDPL) [Member] - BDPL-LEH Loan Agreement [Member] $ in Millions	Dec. 31, 2023 USD ($)
Interest rate	16.00%
Principal amount	$ 4

Face (par) amount of debt instrument at time of issuance.

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Balance Type:	credit
Period Type:	instant