Derivative Financial Instruments and Fair Value of Financial Instruments (Details Textual)	3 Months Ended	12 Months Ended		3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended			6 Months Ended				6 Months Ended					3 Months Ended		6 Months Ended				3 Months Ended		6 Months Ended					3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2012 USD ($) oz	Dec. 31, 2011 USD ($) oz	Jun. 30, 2012 Put Option [Member]	Jun. 30, 2012 Cerro Bayo Mine [Member] USD ($) oz	Jun. 30, 2011 Cerro Bayo Mine [Member] USD ($)	Jun. 30, 2012 Cerro Bayo Mine [Member] USD ($)	Jun. 30, 2011 Cerro Bayo Mine [Member] USD ($)	Dec. 31, 2011 Cerro Bayo Mine [Member] USD ($)	Jun. 30, 2012 Franco-Nevada warrant [Member] USD ($)	Jun. 30, 2011 Franco-Nevada warrant [Member] USD ($)	Jun. 30, 2012 Franco-Nevada warrant [Member] USD ($)	Jun. 30, 2011 Franco-Nevada warrant [Member] USD ($)	Dec. 31, 2011 Franco-Nevada warrant [Member] USD ($)	Jun. 30, 2012 Gold call options sold [Member] USD ($)	Jun. 30, 2011 Gold call options sold [Member]	Jun. 30, 2011 Gold Call Options Expired [Member] oz	Jun. 30, 2012 Gold Put Options Sold [Member] oz	Jun. 30, 2012 Gold put options expired [Member] [Member] USD ($)	Jun. 30, 2012 Gold Call Options Settled [Member] oz	Jun. 30, 2012 Palmarejo gold production royalty [Member] oz	Dec. 31, 2011 Palmarejo gold production royalty [Member]	Jan. 21, 2009 Palmarejo gold production royalty [Member]	Jun. 30, 2012 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Jun. 30, 2011 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Jun. 30, 2012 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Jun. 30, 2011 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Dec. 31, 2011 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Jun. 30, 2012 Silver [Member] Cerro Bayo Mine [Member] USD ($)	Jun. 30, 2012 Commodity [Member] USD ($)	Jun. 30, 2011 Commodity [Member] USD ($)	Jun. 30, 2012 Commodity [Member] USD ($)	Jun. 30, 2011 Commodity [Member] USD ($)	Dec. 31, 2011 Commodity [Member] USD ($)	Jun. 30, 2012 Derivative Instruments Settle in Year 2011 [Member] MXN	Dec. 31, 2011 Derivative Instruments Settle in Year 2011 [Member] MXN	Jun. 30, 2012 Kensington Term Facility [Member] USD ($)	Jun. 30, 2012 Kensington Term Facility [Member] USD ($)	Dec. 31, 2011 Kensington Term Facility [Member] USD ($)	Jun. 30, 2012 Kensington Term Facility [Member] Call Option [Member] oz	Dec. 31, 2011 Kensington Term Facility [Member] Call Option [Member] oz	Jun. 30, 2012 Kensington Term Facility [Member] Put Option [Member] oz	Dec. 31, 2011 Kensington Term Facility [Member] Put Option [Member] oz	Jun. 30, 2012 Maximum [Member] Palmarejo gold production royalty [Member] oz
Derivative [Line Items]
Life of Mine Production, Percentage																						50.00%
Additional Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Payment made for gold on the end of royalty obligation																				4,167
Percentage of Gold Production																				50.00%
Derivative Average Gold Price in Excess of Minimum Contractual Deduction Rate	$ 400
Annual Inflation Compounding Adjustment																				1.00%
Royalty Guarantees, Commitments, Amount																																											400,000
Total gold remain outstanding																				224,710
Fair Value Assumptions, Risk Free Interest Rate	5.30%	5.70%
Derivative, Average Forward Price																				1,630	1,610
Fair value liability of the embedded derivative									146,700,000		146,700,000		159,400,000
Company recognized Mark to Market loss									25,100,000	4,000,000	12,700,000	2,900,000
Realized losses on settlement of the liabilities									11,000,000	9,700,000	24,200,000	17,200,000
Weighted average exchange rate of MXP																																		13.37	12.40
Foreign exchange contracts of MXP																							26,100,000		26,100,000		25,500,000
Fair value of foreign exchange contracts																							(400,000)		(400,000)		(3,200,000)
Mark-to-market gains and losses on forward foreign exchange contract																							100,000	(700,000)	2,800,000	300,000
Mark-to-market Realized gains on forward foreign exchange contract																							(1,200,000)	900,000	(1,900,000)	1,100,000
Gold under collars protection																																							111,000	136,000	156,000	190,000
Weighted Average Put Feature of Each Collar																																				958.16	923.34	951.93
Weighted Average Call Feature of Each Collar																																				1,971.94		1,919.83
Contract expiration date			4 years
Notional ounces																23,750	34,000		25,000
Derivative fair value of derivative liability																													17,900,000		17,900,000		13,200,000
Realized loss from transaction														(1.6)				1,400,000
Average strike price															1,737.68
Unrealized gain																													4,500,000	4,700,000	2,400,000	0
Received silver in connection with sales of asset				125,000
Number of Equal Quarterly Installments to be Delivered				6
Company recognized mark to market gain				300,000	(400,000)	300,000	500,000
Fair value of the contract				1,700,000		1,700,000		2,300,000																				20,200,000
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Outstanding provisionally priced sales consists of silver	400,000	200,000
Outstanding provisionally priced sales consists of Gold	5,698	9,701
Outstanding provisionally priced sales	19,900,000	22,500,000
Fair value of gold and silver including embedded derivative		$ 21,700,000