Note 5 - Concentration of Risk - Product Sales (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue from operations	$ 91,022	$ 116,661
Refinery Operations [Member]
Revenue from operations	$ 89,915	$ 114,640
% of revenue	100.00%	100.00%
LPG Mix [Member] | Refinery Operations [Member]
Revenue from operations	$ 61	$ 55
% of revenue	0.10%	0.00%
Naphtha [Member] | Refinery Operations [Member]
Revenue from operations	$ 18,113	$ 20,729
% of revenue	20.10%	20.70%
Jet Fuel [Member] | Refinery Operations [Member]
Revenue from operations	$ 27,394	$ 35,345
% of revenue	30.50%	35.90%
HOBM [Member] | Refinery Operations [Member]
Revenue from operations	$ 20,535	$ 33,488
% of revenue	22.80%	18.30%
AGO [Member] | Refinery Operations [Member]
Revenue from operations	$ 23,812	$ 25,023
% of revenue	26.50%	25.10%