Inventories (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Metals inventory	$ 0	$ 477
In-process inventory		307
Material and supplies	330	713
Inventories	330	1,497
Inventory write down charged to cost of metals sold		1,200
Inventory write down charged to depreciation expense		$ 700
Velardena properties | Materials and supplies inventory
Obsolescence charge reflected in shutdown costs	$ 300