XML 49 R33.htm IDEA: XBRL DOCUMENT v3.10.0.1
INVENTORIES - Schedule of Inventory, Current (Details) - USD ($)
$ in Thousands
Jun. 30, 2018
Dec. 31, 2017
Inventory Disclosure [Abstract]    
Concentrates and work-in-progress $ 7,426 $ 14,118
Raw materials and consumables 2,846 2,432
Inventory, net $ 10,272 $ 16,550