INVENTORIES AND SUPPLIES (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Oil and oil products	$ 33,603	$ 62,111
Supplies and drums	78,132	68,547
Solvent and solutions	8,868	9,355
Modular camp accommodations	15,126	15,776
Other	13,792	12,874
Total inventories and supplies	$ 149,521	$ 168,663