BUSINESS SEGMENTS - Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment information [Line Items]
Property, plant and equipment, net	$ 108,234				$ 95,140				$ 108,234	$ 95,140
Net sales	86,367	$ 100,094	$ 110,954	$ 100,135	90,318	$ 87,883	$ 80,915	$ 67,313	397,550	326,429	$ 192,803
United States
Segment information [Line Items]
Property, plant and equipment, net	76,957				59,862				76,957	59,862
Net sales									309,826	221,847	116,083
Canada
Segment information [Line Items]
Property, plant and equipment, net	210				198				210	198
Net sales									17,688	30,126	23,377
United Arab Emirates
Segment information [Line Items]
Net sales									6,614	4,093	1,768
Norway
Segment information [Line Items]
Net sales									5,003	990	1,771
Germany
Segment information [Line Items]
Property, plant and equipment, net	29,499				27,442				29,499	27,442
Net sales									4,900	4,067	5,397
Ukraine
Segment information [Line Items]
Net sales									3,824	3,594	1,307
France
Segment information [Line Items]
Property, plant and equipment, net	50				377				50	377
Net sales									3,643	4,581	3,032
Egypt
Segment information [Line Items]
Net sales									3,366	2,419	2,721
Oman
Segment information [Line Items]
Net sales									3,197	2,112	4,132
South Korea
Segment information [Line Items]
Net sales									2,964	2,263	1,173
Russia
Segment information [Line Items]
Property, plant and equipment, net	1,495				7,256				1,495	7,256
Net sales									2,942	4,117	4,504
Belgium
Segment information [Line Items]
Net sales									2,365	3,386	1,628
Netherlands
Segment information [Line Items]
Net sales									2,181	2,427	3,088
Australia
Segment information [Line Items]
Net sales									2,151	873	1,010
Sweden
Segment information [Line Items]
Net sales									2,016	2,339	2,009
Indonesia
Segment information [Line Items]
Net sales									1,934	1,201	409
India
Segment information [Line Items]
Net sales									1,831	4,291	2,927
Bahrain
Segment information [Line Items]
Net sales									1,820	1,065	45
Spain
Segment information [Line Items]
Net sales									1,706	1,083	1,126
Rest of the world
Segment information [Line Items]
Property, plant and equipment, net	$ 23				$ 5				23	5
Net sales									$ 17,579	$ 29,555	$ 15,296