Liquidity and Capital Resources (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended			3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2012 Expected results	Sep. 30, 2012 Expected results T	Sep. 30, 2012 Velardena Operations Expected results T	Dec. 31, 2012 San Mateo drift and other mines Expected results	Dec. 31, 2012 El Quevar project Expected results	Dec. 31, 2012 South America and Mexico exploration properties Expected results	Dec. 31, 2012 Gold Expected results USDperounce	Dec. 31, 2012 Silver Expected results USDperounce
Liquidity and Capital Resources
Cash and short-term investments	$ 54,000,000		$ 54,000,000		$ 41,500,000
Number of shares of common stock per capital unit (in shares)	1
Term of warrants	5 years
Number of common shares which can be purchased with each warrant	0.5		0.5
Net proceeds from issuance and sale of the Company's common stock	36,900,000		36,891,000
Short term investments	417,000		417,000
Expected metal prices during the fourth quarter 2012 (in dollar per ounce)											1,500	30.00
Gross margin from sale of metal during the fourth quarter 2012					(1,000,000)
Sale price of exploration property			2,535,000	404,000	2,000,000
Capital and development costs during the fourth quarter 2012			7,118,000	6,230,000				7,500,000
Maintenance and project evaluation costs during the fourth quarter 2012									1,500,000
Exploration activities and property holding costs during the fourth quarter 2012	1,207,000	4,639,000	5,419,000	12,645,000						1,500,000
General and administrative costs during the fourth quarter 2012	1,934,000	1,836,000	5,787,000	6,242,000	2,000,000
Other working capital					$ 1,000,000
Ramp to tonnes of daily production						1,150	850