PREPAID EXPENSES AND OTHER ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid license	$ 605	$ 1,209
Prepaid insurance premiums	1,767	0
Spare parts	2,330	1,857
Insurance receivable	0	1,148
Cash held in escrow by AMAK	1,877	0
Other prepaid expenses and assets	437	733
Total prepaid expenses and other assets	$ 7,016	$ 4,947