Derivative Financial Instruments (Details 1) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Prepaid expenses and other [Member]
Fair value of the derivative instruments
Fair value of derivative asset	$ 1,392	$ 3,925
Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	778	1,887
Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	13,878	14,405
Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	1,404	7,507
Palmarejo gold production royalty [Member] | Current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	13,878	14,405
Palmarejo gold production royalty [Member] | Non-current portion of royalty obligation [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	1,404	7,507
Put and call options, net [Member]
Fair value of the derivative instruments
Fair value of derivative asset	1,250
Derivative Liability, Fair Value	123	1,039
Put and call options, net [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Fair value of derivative asset		3,882
Put and call options, net [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	123	1,039
Concentrate sales contracts [Member] | Prepaid expenses and other [Member]
Fair value of the derivative instruments
Fair value of derivative asset	142	43
Concentrate sales contracts [Member] | Accrued liabilities and other [Member]
Fair value of the derivative instruments
Derivative Liability, Fair Value	$ 655	$ 848