INVENTORIES AND SUPPLIES (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Inventory Disclosure [Abstract]
Oil and oil products	$ 57,554	$ 57,554		$ 52,158
Supplies and drums	92,995	92,995		90,610
Solvent and solutions	8,575	8,575		8,566
Modular camp accommodations	2,699	2,699		15,255
Other	10,717	10,717		11,839
Total inventories and supplies	172,540	172,540		$ 178,428
Transfer of inventory to property, plant and equipment	$ 12,600	$ 12,641	$ 0