Commitments and Contigencies (Details Textual)	Jun. 30, 2017	Oct. 02, 2014 USD ($)	Oct. 14, 2009 m
Business Acquisition [Line Items]
Percentage of labor force covered by collective bargaining agreements	10.00%
Maximum Height for Temporary Restriction on Mining | m			4,400
Palmarejo gold production royalty [Member]
Business Acquisition [Line Items]
Production to be sold, percent		50.00%
Price per ounce under agreement		$ 800
Aggregate deposit to be received		$ 22,000,000