Derivative Financial Instruments and Fair Value of Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	$ (52,050)	$ (117,094)	$ (82,227)
Fair value adjustments, net	(49,161)	(85,485)	(79,919)
Concentrate sales contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Sales of metals	2,505	1,636	1,191
Gold lease facility [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	(132)	2,885	(6,292)
Forward foreign exchange contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Production costs applicable to sales	383	1,638	1,474
Fair value adjustments	(3,192)	(1,330)	1,335
Forward gold contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	35	425
Silver ounces receivables [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	(276)	1,594
Palmarejo gold royalty [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	(40,046)	(83,989)	(78,014)
Franco-Nevada warrant [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	0	3,451	3,340
Put and call options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments	$ (8,438)	$ (11,795)	$ (2,953)