Commitments and Contigencies (Details Textual)			3 Months Ended		6 Months Ended
	Oct. 02, 2014 USD ($)	Jan. 21, 2009	Jun. 30, 2015 USD ($) oz / Month oz	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) oz	Oct. 14, 2009 m
Business Acquisition [Line Items]
Price per ounce under agreement			$ 412		$ 412
Maximum Height for Temporary Restriction on Mining | m						4,400
NSR royalty percentage				3.40%
NSR royalty maximum amount				$ 39,400,000
Percentage of labor force covered by collective bargaining agreements			11.70%		11.70%
Purchased royalty		50.00%
Royalty agreement minimum obligation for the period | oz			400,000
Royalty Agreement Minimum Obligation for Per Month | oz / Month			4,167
Royalty Agreement Period		8 years
Rochester [Member]
Business Acquisition [Line Items]
Royalty expenses					$ 0
Gold price per ounce for maximum royalty range			$ 23.60
Maximum royalty payable			$ 250,000		250,000
Maximum royalty range for gold price per ounce			5.00%
Palmarejo gold production royalty [Member]
Business Acquisition [Line Items]
Termination payment	$ 2,000,000
Production to be sold, percent	50.00%
Price per ounce under agreement	$ 800
Aggregate deposit to be received	$ 22,000,000
Deposits received under gold stream agreement			$ 5,000,000		$ 10,000,000
Rochester Royalty Obligation [Member] | Maximum [Member]
Business Acquisition [Line Items]
Payable ounces under royalty obligation | oz			11,000,000		11,000,000
Remaining ounces under royalty obligation | oz			28,400,000		28,400,000