INVENTORIES AND SUPPLIES (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Inventory [Line Items]
Inventories and supplies	$ 219,499	$ 220,498
Oil and oil related products
Inventory [Line Items]
Inventories and supplies	76,106	76,209
Supplies
Inventory [Line Items]
Inventories and supplies	120,814	120,007
Solvent and solutions
Inventory [Line Items]
Inventories and supplies	9,145	8,812
Other
Inventory [Line Items]
Inventories and supplies	$ 13,434	$ 15,470