PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Subtotal	$ 651,787	$ 407,141
Less accumulated depreciation	180,877	143,279
Property and equipment — net	470,910	263,862
Equipment and vehicles
Property, Plant and Equipment [Line Items]
Subtotal	646,800	402,641
Leasehold improvements
Property, Plant and Equipment [Line Items]
Subtotal	$ 4,987	$ 4,500