INVENTORIES AND SUPPLIES (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory [Line Items]
Inventories and supplies	$ 220,498	$ 214,744
Oil and oil related products
Inventory [Line Items]
Inventories and supplies	76,209	75,408
Supplies and drums
Inventory [Line Items]
Inventories and supplies	120,007	115,128
Solvent and solutions
Inventory [Line Items]
Inventories and supplies	8,812	9,973
Other
Inventory [Line Items]
Inventories and supplies	$ 15,470	$ 14,235