SEGMENT REPORTING - Revenue by Country (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 859,111	$ 1,062,388
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	460,484	652,879
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	113,660	90,459
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	54,347	64,465
Denmark
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	27,311	12,426
Sweden
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	18,789	34,578
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	18,430	23,432
Indonesia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	16,739	3,108
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	14,443	5,678
Finland
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	14,118	10,161
Belgium
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	9,145	8,226
Philippines
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	6,702	0
Taiwan - Republic of China
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	6,154	11,690
India
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	6,095	5,642
Italy
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	6,013	14,164
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	5,897	14,690
Saudi Arabia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	5,243	8,035
South Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	5,033	3,586
Brazil
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	4,800	9,042
Vietnam
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	3,801	5,764
Bahrain
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	2,628	5,286
Chile
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	2,533	5,597
Nigeria
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	1,019	12,211
Aggregate of all other countries, each with less than $5 million in revenues
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 55,727	$ 61,269