Asset Retirement and Reclamation Liabilities (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Summary of activity in the Velardena Operations ARO
Beginning balance	$ 2,602,000
Accretion expense	200,000	184,000
Ending balance	2,685,000	2,602,000
Risk-free rate (as a percent)	1.60%
Velardena Properties
Asset Retirement and Reclamation Liabilities
Third party estimated closure plan			1,900,000
Estimated ARO and ARC recorded at the time of the acquisition	3,500,000
Amortization expense related to the ARC	200,000	200,000
Summary of activity in the Velardena Operations ARO
Beginning balance	2,467,000	2,080,000
Changes in estimates, and other	(85,000)	203,000
Accretion expense	200,000	184,000
Ending balance	2,582,000	2,467,000
El Quevar Project
Summary of activity in the Velardena Operations ARO
Ending balance	$ 100,000	$ 100,000