Asset Retirement Obligations (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Jun. 30, 2012	Dec. 31, 2015
Asset Retirement and Reclamation Liabilities
Property, plant and equipment, net	$ 10,254,000			$ 11,125,000
Summary of activity in the Velardena Operations ARO
Beginning balance	2,546,000
Accretion expense	51,000	$ 52,000
Ending balance	2,297,000
Velardena properties
Asset Retirement and Reclamation Liabilities
ARO arising in the period			$ 3,500,000
Amortization expense related to the ARC	20,000
Summary of activity in the Velardena Operations ARO
Beginning balance	2,480,000	2,582,000
Changes in estimates, and other	(293,000)	(300,000)
Accretion expense	50,000	52,000
Ending balance	2,237,000	$ 2,334,000
ARO arising in the period (acquired at merger)			3,500,000
Velardena properties | Asset retirement cost
Asset Retirement and Reclamation Liabilities
Property, plant and equipment, net			$ 1,900,000
El Quevar Project
Summary of activity in the Velardena Operations ARO
Beginning balance	100,000
Ending balance	$ 100,000