Note 4 - Revenue and Segment Information - Identifiable Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Identifiable assets	$ 106,077	$ 83,904
Corporate, Non-Segment [Member]
Identifiable assets	3,048	1,709
Refinery Operations [Member] \| Operating Segments [Member]
Identifiable assets	86,565	64,359
Tolling and Terminaling [Member] \| Operating Segments [Member]
Identifiable assets	$ 16,464	$ 17,836

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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+ Details