Derivative Financial Instruments (Details Textual)	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) oz $ / oz $ / XAG	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) oz $ / oz $ / XAG	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) oz $ / XAU $ / XAG	Jan. 21, 2009
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Gain (loss) on derivative instruments	$ 2,754,000	$ (8,282,000)	$ (2,130,000)	$ (19,717,000)
Fair Value Assumptions, Risk Free Interest Rate	10.281%	11.80%
Price per ounce under agreement	$ 412		$ 412
Put Option [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Contract expiration date			3 years
Franco-Nevada warrant [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Fair value liability of the embedded derivative					$ 21,900,000
Realized losses			$ (7,800,000)	(11,700,000)
Palmarejo gold production royalty [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Production to be sold, percent						50.00%
Payment made for gold on the end of royalty obligation | oz	4,167		4,167
Remaining ounces under royalty obligation | oz	59,913		59,913
Percentage of Gold Production	50.00%		50.00%
Annual Inflation Compounding Adjustment	1.00%		1.00%
Concentrate Sales Contracts [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Unrealized Gain (Loss) on Derivatives	$ (623,000)	$ 7,000	$ 291,000	872,000
Gold Put Purchase and Call Sold Options Net [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative Liability, Fair Value	123,000		123,000		$ 1,039,000
Fair value of the contract	1,250,000		1,250,000
Commodity [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Mark-to-market gains and (losses) on forward foreign exchange contract			700,000	(800,000)
Silver and gold options [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Gain (loss) on derivative instruments	$ 1,232,000	$ (1,374,000)	185,000
Unrealized Gain (Loss) on Derivatives			$ 1,000,000	$ (2,868,000)
Maximum [Member] | Palmarejo gold production royalty [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Payable ounces under royalty obligation | oz	400,000		400,000
Derivative Instruments Settle in Year One [Member] | Gold Put Option [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Weighted Average Strike Price of Put Options | $ / XAU					1,050
Derivative Instruments Settle in Year One [Member] | Silver concentrate sales agreements [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ (12,505,000)		$ (12,505,000)
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Outstanding provisionally priced sales consists of silver | oz	789,479		789,479
Derivative Average Price | $ / oz	15.84		15.84
Derivative Instruments Settle in Year One [Member] | Gold concentrates sales agreements [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ (52,776,000)		$ (52,776,000)
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Outstanding provisionally priced sales consists of Gold | oz	44,238		44,238
Derivative Average Price | $ / oz	1,193		1,193
Derivative Instruments Settle in Year One [Member] | Silver put options purchased [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ (15,300,000)		$ (15,300,000)
Derivative Instruments Settle in Year One [Member] | Silver Put Options Sold [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ (13,950,000)		$ (13,950,000)
Notional ounces | oz	900,000		900,000
Weighted Average Strike Price of Put Options | $ / XAG	15.50		15.50
Derivative Instruments Settle in Year One [Member] | Kensington Term Facility [Member] | Gold put options purchased [Member] | Put Option [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Weighted Average Strike Price of Put Options | $ / XAU					1,200
Derivative Instruments Settle in Year One [Member] | Kensington Term Facility [Member] | Silver put options purchased [Member] | Put Option [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Weighted Average Strike Price of Put Options | $ / XAG	17.00		17.00		18.00
Derivative Financial Instruments, Assets [Member] | Gold put options purchased [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Notional ounces | oz					24,000
Derivative Financial Instruments, Assets [Member] | Silver put options purchased [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Notional ounces | oz					1,300,000
Derivative Instruments Settle in Year Two [Member] | Silver concentrate sales agreements [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ 0		$ 0
Notional ounces | oz	0		0
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative Average Price | $ / oz	0		0
Derivative Instruments Settle in Year Two [Member] | Gold concentrates sales agreements [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ 0		$ 0
Notional ounces | oz	0		0
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative Average Price | $ / oz	0		0
Derivative Instruments Settle in Year Two [Member] | Silver put options purchased [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ 0		$ 0
Notional ounces | oz	0		0
Derivative Instruments Settle in Year Two [Member] | Silver Put Options Sold [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ 0		$ 0
Weighted Average Strike Price of Put Options | $ / XAG					16.00
Outstanding Put Options of Silver | oz	0		0
Derivative Instruments Settle Thereafter [Member] | Silver concentrate sales agreements [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ 0		$ 0
Notional ounces | oz	0		0
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative Average Price | $ / oz	0		0
Derivative Instruments Settle Thereafter [Member] | Gold concentrates sales agreements [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ 0		$ 0
Notional ounces | oz	0		0
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative Average Price | $ / oz	0		0
Derivative Instruments Settle Thereafter [Member] | Silver put options purchased [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ 0		$ 0
Notional ounces | oz	0		0
Derivative Instruments Settle Thereafter [Member] | Silver Put Options Sold [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Derivative, Notional Amount	$ 0		$ 0
Outstanding Put Options of Silver | oz	0		0
Prepaid Expenses and Other Current Assets [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Fair value of the contract	$ 1,392,000		$ 1,392,000		$ 3,925,000
Prepaid Expenses and Other Current Assets [Member] | Gold Put Purchase and Call Sold Options Net [Member]
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Fair Value, Asian Put Options	$ 1,100,000		$ 1,100,000
Fair value of the contract					$ 3,882,000