Derivative Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments, net	$ (8,282)	$ 66,754	$ (19,717)	$ 84,550
Fair value adjustments, net	(6,438)	66,290	(17,259)	82,958
Mexican peso forward purchase contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments, net	(10)	(2,260)	957	(1,522)
Concentrate Sales Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Sales of Metals	7	(667)	872	(2,422)
Forward foreign exchange contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Costs applicable to sales	0	203	924	(830)
Fair value adjustments, net	(10)	(662)	957	(1,522)
Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments, net	0	1,598	0	0
Palmarejo gold production royalty [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments, net	(5,061)	61,066	(15,296)	75,495
Gold Put Purchase and Call Sold Options Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments, net	$ (1,374)	$ 6,350	$ (2,868)	$ 10,577