Derivative Financial Instruments (Details 2) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015		Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Costs applicable to sales	[1]	$ 105,408	$ 120,237	[2]	$ 307,428	$ 354,397	[3]
Fair value adjustments, net		(961)	5,786		(13,235)	3,657
Fair value adjustments, net		(894)	4,116		(7,070)	4,858
Concentrate Sales Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives		(784)	82		378	373
Embedded Derivative Financial Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments, net		(110)	2,983		(5,866)	1,823
Silver and gold options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives		0			0
Fair value adjustments, net		0	$ 1,051		$ (1,582)	1,238
Derivative, Gain (Loss) on Derivative, Net		$ 0				$ 2,662

[1] Excludes amortization.

[2] Excludes amortization

[3] Excludes amortization