INVESTMENT IN AMAK - Summary of Financial Position (Details) - AMAK - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Current assets	$ 35,658	$ 44,093
Noncurrent assets	197,093	212,291
Total assets	232,751	256,384
Current liabilities	19,201	17,160
Long term liabilities	74,111	77,366
Stockholders' equity	139,439	161,858
Total liabilities and Shareholders' equity	$ 232,751	$ 256,384