Commitments and Contigencies (Details Textual) oz in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)	Mar. 31, 2017 oz	Oct. 02, 2014 USD ($)	Oct. 14, 2009 m
Business Acquisition [Line Items]
Percentage of labor force covered by collective bargaining agreements		10.00%
NSR royalty percentage	3.40%
NSR royalty maximum amount	$ 39,400,000
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
Rochester Royalty Obligation [Member]
Business Acquisition [Line Items]
Payable ounces under royalty obligation | oz		15.9