Derivative Financial Instruments and Fair Value of Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	$ (37,648)	$ (53,351)	$ (44,722)	$ (71,051)
Fair value adjustments, net	(35,663)	(51,950)	(44,212)	(65,667)
Concentrate Sales Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Sales of Metals	1,591	1,466	2,050	4,339
Forward foreign exchange contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Production costs applicable to sales	394	(65)	(1,540)	1,045
Fair value adjustments	621	(4,089)	3,394	(3,791)
Gold lease facility [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	0	0	0	(132)
Forward gold contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	0	0	0	35
Silver Ounces Receivables [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	280	(554)	302	(90)
Palmarejo gold production royalty [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	(34,266)	(26,464)	(45,771)	(46,505)
Put and call options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	$ (4,283)	$ (22,244)	$ (2,647)	$ (20,568)