Impairment of Long Lived Assets (Details) (USD $)	3 Months Ended		6 Months Ended	12 Months Ended
	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Impairment of long lived assets
Net deferred tax asset (liability)	$ 0		$ 0	$ 0	$ 0
Income Tax Expense (Benefit)					(49,686,000)
Details of components of the impairment of long lived assets
Impairment of long lived assets					243,985,000
Mineral Properties
Details of components of the impairment of long lived assets
Impairment of long lived assets					217,524,000
Exploration Properties
Details of components of the impairment of long lived assets
Impairment of long lived assets					12,131,000
Velardena Properties
Impairment of long lived assets
Net deferred tax asset (liability)	0		0		0
Income Tax Expense (Benefit)					(45,000,000)
Enterprise value (in dollars per ounce)		0.29
Details of components of the impairment of long lived assets
Net Book Value - Beginning Balance		260,205,000	30,795,000	23,869,000
Impairment of long lived assets		229,410,000	5,916,000	0	235,326,000
Net Book Value After Impairment	23,869,000	30,795,000	23,869,000		23,869,000
Adjustments relating to long lived assets	100,000
Velardena Properties | Mineral Properties
Details of components of the impairment of long lived assets
Net Book Value - Beginning Balance		232,805,000	21,197,000
Impairment of long lived assets		211,608,000	5,916,000		217,524,000
Net Book Value After Impairment	15,384,000	21,197,000	15,384,000		15,384,000
Velardena Properties | Exploration Properties
Details of components of the impairment of long lived assets
Net Book Value - Beginning Balance		3,472,000
Impairment of long lived assets		3,472,000			3,472,000
Velardena Properties | Tangible Assets
Details of components of the impairment of long lived assets
Net Book Value - Beginning Balance		23,928,000
Impairment of long lived assets		14,330,000
Net Book Value After Impairment	8,485,000	9,598,000	8,485,000		8,485,000
San Diego Exploration Property
Details of components of the impairment of long lived assets
Net Book Value - Beginning Balance		9,260,000	832,000	601,000
Impairment of long lived assets		8,428,000	231,000	0	8,659,000
Net Book Value After Impairment	601,000	832,000	601,000		601,000
Percentage of ownership interest				50.00%
Distance of exploration property from other operations				10
San Diego Exploration Property | Exploration Properties
Details of components of the impairment of long lived assets
Net Book Value - Beginning Balance		9,260,000	832,000
Impairment of long lived assets		8,428,000	231,000		8,659,000
Net Book Value After Impairment	$ 601,000	$ 832,000	$ 601,000		$ 601,000
Silver
Impairment of long lived assets
Decrease in metal prices (as a percent)		34.00%
Gold
Impairment of long lived assets
Decrease in metal prices (as a percent)		26.00%