The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Note 7 - Intangible Assets, Net (Details Textual) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Mar. 31, 2018	Feb. 29, 2016	Nov. 30, 2015	Dec. 31, 2019	Dec. 31, 2018
Amortization of Intangible Assets, Total				$ 2,700	$ 2,500
Impairment of Intangible Assets, Finite-lived					189
Customer Relationships [Member] \| Crude Oil Pipeline Services [Member]
Impairment of Intangible Assets, Finite-lived					200
Customer Relationships [Member] \| Minimum [Member]
Finite-Lived Intangible Asset, Useful Life				5 years
Customer Relationships [Member] \| Maximum [Member]
Finite-Lived Intangible Asset, Useful Life				20 years
Customer Contracts [Member] \| Crude Oil Pipeline Services [Member]
Impairment of Intangible Assets, Finite-lived					$ 200
Asphalt Terminalling Services [Member] \| Customer Relationships [Member]
Finite-lived Intangible Assets Acquired	$ 7,600	$ 8,400
Crude Oil Pipeline Services [Member] \| Customer Relationships [Member]
Finite-lived Intangible Assets Acquired			$ 3,200