INVENTORIES AND SUPPLIES (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Oil and oil products	$ 55,872	$ 52,158
Supplies and drums	91,210	90,610
Solvent and solutions	8,865	8,566
Modular camp accommodations	14,859	15,255
Other	11,232	11,839
Total inventories and supplies	$ 182,038	$ 178,428