Derivative Financial Instruments and Fair Value of Financial Instruments (Details 2) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments net	$ (13,088)	$ (42,563)	$ (19,462)	$ (46,683)
Forward foreign exchange contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Production costs applicable to sales	859	489	1,111	40
Fair value adjustments net	(707)	(1,649)	298	(1,192)
Gold lease facility [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments net	0	(2,137)	(132)	(2,729)
Forward gold contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments net	0	0	35	0
Silver Ounces Receivables [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments net	(368)	0	464	0
Palmarejo gold production royalty [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments net	(13,731)	(33,663)	(20,041)	(38,512)
Franco-Nevada warrant [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments net	0	1,030	0	2,333
Put and call options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair value adjustments net	2,374	(6,097)	1,676	(6,674)
Concentrate Sales Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Sales of Metals	$ (1,515)	$ (536)	$ (2,873)	$ 51