Liquidity, Capital Resources and Going Concern (Details)				3 Months Ended	12 Months Ended
	Feb. 11, 2016 USD ($) item $ / shares shares	Jan. 19, 2016 item	Oct. 27, 2015 USD ($) item	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Liquidity and Capital Resources
Cash and cash equivalents				$ 4,077,000		$ 4,077,000	$ 8,579,000	$ 19,146,000
Difference of cash and cash equivalents between periods				4,500,000		4,500,000
Shutdown and care and maintenance costs						1,228,000	2,457,000
Exploration expenditures						3,634,000	5,528,000
General and administrative expenses						4,242,000	4,642,000
Proceeds from sales of non strategic property and equipment						500,000
Proceeds from VAT refunds						800,000
Reduction in working capital						1,300,000
Operating Leases, Income Statement, Lease Revenue						653,000
Costs and expenses forecasted						38,229,000	$ 22,567,000
Sentient Loan | Convertible loan
Liquidity and Capital Resources
Principal amount of loan			$ 5,000,000
Consecutive trading days, period | item			15
Interest rate (as a percent)			9.00%
Subsequent Event | Sentient Loan | Convertible loan
Liquidity and Capital Resources
Amount of debt converted to equity	$ 3,900,000
Amount of accrued interest converted to equity	$ 100,000
Equity shares issued upon conversion of debt | shares	23,335,000
Exercise price per share of shares converted from debt | $ / shares	$ 0.172
Stock price trigger (as a percent)	90.00%	90.00%
Consecutive trading days, period | item	15	15
Debt outstanding	$ 1,100,000
Amount payable on failing to convert debt and accrued interest	$ 1,200,000
Forecast
Liquidity and Capital Resources
Cash and cash equivalents					$ 500,000
General and administrative expenses					3,400,000
Reduction in working capital					(1,100,000)
Costs and expenses forecasted					8,400,000
Other exploration and property holding costs					800,000
Exploration, project assessment and development costs					1,400,000
Payments for equity taxes owned in foreign jurisdiction					400,000
Period Preceding Loan Closure Date | Sentient Loan | Convertible loan
Liquidity and Capital Resources
Stock price trigger (as a percent)			90.00%
Period Preceding Loan Conversion Date | Sentient Loan | Convertible loan
Liquidity and Capital Resources
Stock price trigger (as a percent)			90.00%
Period Preceding Loan Conversion Date | Subsequent Event | Sentient Loan | Convertible loan
Liquidity and Capital Resources
Stock price trigger (as a percent)	90.00%
Consecutive trading days, period | item	15
Velardena properties
Liquidity and Capital Resources
Negative operating margin						2,500,000
Shutdown and care and maintenance costs						1,200,000
Exploration expenditures						3,600,000
Velardena properties | Forecast
Liquidity and Capital Resources
Shutdown and care and maintenance costs					1,200,000
El Quevar Project
Liquidity and Capital Resources
Shutdown and care and maintenance costs						1,100,000
El Quevar Project | Forecast
Liquidity and Capital Resources
Ongoing maintenance activities and property holding costs					500,000
Oxide Plant Asset Group | Velardena properties
Liquidity and Capital Resources
Shutdown and care and maintenance costs				$ 1,200,000
Net revenue from lease						$ 500,000
Oxide Plant Asset Group | Velardena properties | Forecast
Liquidity and Capital Resources
Operating Leases, Income Statement, Lease Revenue					$ 4,800,000