Quarterly report pursuant to Section 13 or 15(d)

PLANT, PIPELINE AND EQUIPMENT (Details)

v3.8.0.1
PLANT, PIPELINE AND EQUIPMENT (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Property, Plant and Equipment [Line Items]      
Total plant, pipeline and equipment $ 256,010   $ 244,982
Less accumulated depreciation (65,871)   (63,240)
PLANT, PIPELINE, AND EQUIPMENT, NET (Note 9) 190,139   181,742
Interest capitalized for construction 304 $ 374  
Capitalized labor costs 1,200 800  
Amortization relating to the platinum catalyst 0 $ 25  
Platinum Catalyst Metal [Member]      
Property, Plant and Equipment [Line Items]      
Total plant, pipeline and equipment 1,612   1,612
Land [Member]      
Property, Plant and Equipment [Line Items]      
Total plant, pipeline and equipment 5,428   5,428
Plant, Pipeline and Equipment [Member]      
Property, Plant and Equipment [Line Items]      
Total plant, pipeline and equipment 188,529   186,946
Construction in Progress [Member]      
Property, Plant and Equipment [Line Items]      
Total plant, pipeline and equipment $ 60,441   $ 50,996