Derivative Financial Instruments and Fair Value of Financial Instruments (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Prepaid expenses and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	$ 814	$ 2,987
Other non-current Assets [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	1,063
Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value		4,030
Derivative Liability, Fair Value	7,196
Other long-term liabilities [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value		13,277
Derivative Liability, Fair Value	14,669
Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	37,206	28,745
Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	122,194	133,258
Gold lease facility [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value		0
Gold lease facility [Member] | Other non-current Assets [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value		0
Gold lease facility [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value		2,213
Gold lease facility [Member] | Other long-term liabilities [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value		0
Gold lease facility [Member] | Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value		0
Gold lease facility [Member] | Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value		0
Gold forward contracts [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value		425
Gold forward contracts [Member] | Other non-current Assets [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value		0
Gold forward contracts [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value		0
Gold forward contracts [Member] | Other long-term liabilities [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value		0
Gold forward contracts [Member] | Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value		0
Gold forward contracts [Member] | Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value		0
Silver ounces receivable from Mandalay [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	814	531
Silver ounces receivable from Mandalay [Member] | Other non-current Assets [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	1,063
Silver ounces receivable from Mandalay [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Silver ounces receivable from Mandalay [Member] | Other long-term liabilities [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Silver ounces receivable from Mandalay [Member] | Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Silver ounces receivable from Mandalay [Member] | Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Forward foreign exchange contract [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	328
Forward foreign exchange contract [Member] | Other non-current Assets [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	0
Forward foreign exchange contract [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	3,188	323
Forward foreign exchange contract [Member] | Other long-term liabilities [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Forward foreign exchange contract [Member] | Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Forward foreign exchange contract [Member] | Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Palmarejo gold royalty [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	0
Palmarejo gold royalty [Member] | Other non-current Assets [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	0
Palmarejo gold royalty [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Palmarejo gold royalty [Member] | Other long-term liabilities [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Palmarejo gold royalty [Member] | Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	37,206	28,745
Palmarejo gold royalty [Member] | Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	122,194	133,258
Put and call options, net [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	0
Put and call options, net [Member] | Other non-current Assets [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	0
Put and call options, net [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	3,183	1,471
Put and call options, net [Member] | Other long-term liabilities [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	14,669	13,277
Put and call options, net [Member] | Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Put and call options, net [Member] | Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Concentrate sales contracts [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	1,703
Concentrate sales contracts [Member] | Other non-current Assets [Member]
Fair value of the derivative instruments
Derivative Asset, Fair Value	0	0
Concentrate sales contracts [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	825	23
Concentrate sales contracts [Member] | Other long-term liabilities [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Concentrate sales contracts [Member] | Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	0	0
Concentrate sales contracts [Member] | Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	$ 0	$ 0