PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
PROPERTY AND EQUIPMENT
Total property and equipment	$ 839,032	$ 773,635
Accumulated depreciation and amortization	(382,648)	(316,998)
Property and equipment, net	456,384	456,637
Depreciation and amortization of plant and equipment	70,799	66,561	$ 41,423
Cell development costs
PROPERTY AND EQUIPMENT
Total property and equipment	203,217	186,170
Land and improvements
PROPERTY AND EQUIPMENT
Total property and equipment	74,298	65,953
Buildings and improvements
PROPERTY AND EQUIPMENT
Total property and equipment	138,659	128,206
Railcars
PROPERTY AND EQUIPMENT
Total property and equipment	17,299	17,299
Vehicles, vessels and other equipment
PROPERTY AND EQUIPMENT
Total property and equipment	350,950	331,167
Construction in progress
PROPERTY AND EQUIPMENT
Total property and equipment	$ 54,609	$ 44,840