Derivative Financial Instruments and Fair Value of Financial Instruments (Details Textual)				3 Months Ended			3 Months Ended			3 Months Ended					3 Months Ended				3 Months Ended							3 Months Ended
	Mar. 31, 2012 USD ($) oz	Dec. 31, 2011 USD ($) oz	Mar. 31, 2012 Put Option [Member]	Mar. 31, 2012 Cerro Bayo Mine [Member] USD ($) oz	Mar. 31, 2011 Cerro Bayo Mine [Member] USD ($)	Dec. 31, 2011 Cerro Bayo Mine [Member] USD ($)	Mar. 31, 2012 Franco-Nevada warrant [Member] USD ($)	Mar. 31, 2011 Franco-Nevada warrant [Member] USD ($)	Dec. 31, 2011 Franco-Nevada warrant [Member] USD ($)	Mar. 31, 2012 Gold call options sold [Member] USD ($)	Mar. 31, 2011 Gold call options sold [Member] USD ($) oz	Mar. 31, 2011 Gold Put Options Sold [Member] USD ($) oz	Mar. 31, 2012 Gold Put Options Sold [Member] oz	Mar. 31, 2012 Palmarejo gold production royalty [Member] oz	Mar. 31, 2012 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Mar. 31, 2011 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Dec. 31, 2011 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Mar. 31, 2012 Silver [Member] Cerro Bayo Mine [Member] USD ($)	Mar. 31, 2012 Commodity [Member] USD ($)	Mar. 31, 2011 Commodity [Member] USD ($)	Dec. 31, 2011 Commodity [Member] USD ($)	Mar. 31, 2012 Derivative Instruments Settle in Year 2011 [Member]	Mar. 31, 2012 Derivative Instruments Settle in Year 2011 [Member] MXN	Dec. 31, 2011 Derivative Instruments Settle in Year 2011 [Member] MXN	Mar. 31, 2012 Derivative Instruments Settle in Year 2011 [Member] Gold call options sold [Member] oz	Mar. 31, 2012 Kensington Term Facility [Member] USD ($)	Mar. 31, 2012 Kensington Term Facility [Member] Call Option [Member] oz	Mar. 31, 2012 Kensington Term Facility [Member] Put Option [Member] oz
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Payment made for gold on the end of royalty obligation														400,000
Total gold remain outstanding														239,974
Fair value liability of the embedded derivative							$ 171,800,000		$ 159,400,000
Company recognized Mark to Market loss							0	1,100,000
Realized losses on settlement of the liabilities							(13,200,000)	7,500,000
Weighted average exchange rate of MXP																							12.78	0
Foreign exchange contracts of MXP															25,800,000		25,500,000
Fair value of foreign exchange contracts															(500,000)		0
Mark-to-market gains and losses on forward foreign exchange contract															2,700,000	1,000,000
Mark-to-market Realized gains on forward foreign exchange contract															(800,000)	300,000
Gold under collars protection																											136,000	173,000
Weighted Average Put Feature of Each Collar																										954.74
Weighted Average Call Feature of Each Collar																										1,919.83
Contract expiration date			4 years
Notional ounces											11,250	11,250	17,000												14,000
Derivative fair value of derivative liability																			17,900,000		17,700,000
Realized loss from transaction										700,000	(700,000)	0
Average strike price											1,723.11	878.56										2,000	2,000
Unrealized gain																			200,000	(700,000)
Received silver in connection with sales of asset				125,000
Number of Equal Quarterly Installments to be Delivered				6
Third installment received				20,833
Realized gains																			300,000
Company recognized mark to market gain				100,000	800,000
Fair value of the contract	98,000			2,000,000		2,300,000												16,200,000
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Outstanding provisionally priced sales consists of silver	300,000	200,000
Outstanding provisionally priced sales consists of Gold	3,181	9,701
Outstanding provisionally priced sales	16,700,000	22,500,000
Fair value of gold and silver including embedded derivative		$ 21,700,000