Liquidity and Capital Resources (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended	12 Months Ended		3 Months Ended	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2013 Expected results	Jun. 30, 2013 Velardena Operations Severance and other costs	Dec. 31, 2013 Velardena Operations Expected results	Dec. 31, 2013 Velardena Operations Expected results One-time suspension	Mar. 31, 2013 Peruvian exploration properties	Dec. 31, 2013 El Quevar project Expected results
Liquidity and Capital Resources
Cash balance	$ 30,000,000		$ 30,000,000		$ 16,000,000
Net proceeds from sale of exploration concessions			3,842,000	2,494,000					3,500,000
Other proceeds related to joint venture option payments									500,000
Costs related to the suspension						2,300,000
Expected costs related to the suspension								3,000,000
Maintenance activities, property holding costs, and project evaluation costs during 2013							2,500,000			1,000,000
Exploration activities and property holding costs during 2013	1,240,000	1,816,000	2,764,000	4,212,000	2,500,000
General and administrative costs during 2013	1,633,000	1,829,000	3,530,000	3,853,000	3,000,000
Increase (decrease) in working capital, net					$ 2,000,000