Note 5 - Discontinued Operations (Details Textual) - USD ($) $ in Thousands			2 Months Ended	3 Months Ended	12 Months Ended
		Dec. 15, 2020	Feb. 02, 2021	Mar. 31, 2020	Dec. 31, 2021	Dec. 21, 2021	Dec. 31, 2020
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax, Total					$ (0)		$ (39,096)
Pipeline Linefill [Member]
Asset Impairment Charges, Total				$ 4,900
Crude Oil Trucking Services [Member]
Asset Impairment Charges, Total							1,300
Discontinued Operations, Held-for-sale [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax, Total	[1]						(39,096)
Crude Oil Pipeline Services [Member] | Discontinued Operations, Held-for-sale [Member]
Proceeds from Divestiture of Businesses, Held in Escrow						$ 1,400
Exit and Disposal Costs						$ 1,900
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax, Total	[1]						(37,249)
Crude Oil Trucking Services [Member] | Discontinued Operations, Held-for-sale [Member]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax, Total		$ (1,100)	$ (700)				$ (1,847)	[1]

[1] Included in the crude oil trucking services segment is a loss on disposal recorded during December 2020 for the first phase closing of $1.1 million, and a loss on the classification on assets held for sale as of December 31, 2020, for the second phase closing on February 2, 2021, of $0.7 million.