Derivative Financial Instruments and Fair Value of Financial Instruments (Details Textual)	3 Months Ended	12 Months Ended		3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended						9 Months Ended				3 Months Ended		9 Months Ended				3 Months Ended		9 Months Ended					3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2012 USD ($) oz	Dec. 31, 2011 USD ($) oz	Sep. 30, 2012 Put Option [Member]	Sep. 30, 2012 Cerro Bayo Mine [Member] USD ($) oz	Sep. 30, 2011 Cerro Bayo Mine [Member] USD ($)	Sep. 30, 2012 Cerro Bayo Mine [Member] USD ($)	Sep. 30, 2011 Cerro Bayo Mine [Member] USD ($)	Dec. 31, 2011 Cerro Bayo Mine [Member] USD ($)	Sep. 30, 2012 Franco-Nevada warrant [Member] USD ($)	Sep. 30, 2011 Franco-Nevada warrant [Member] USD ($)	Sep. 30, 2012 Franco-Nevada warrant [Member] USD ($)	Sep. 30, 2011 Franco-Nevada warrant [Member] USD ($)	Dec. 31, 2011 Franco-Nevada warrant [Member] USD ($)	Sep. 30, 2011 Gold call options sold [Member]	Sep. 30, 2011 Gold Call Options Expired [Member] oz	Sep. 30, 2012 Gold Put Options Sold [Member] oz	Sep. 30, 2012 Gold put options expired [Member] [Member] USD ($)	Sep. 30, 2012 Palmarejo gold production royalty [Member] oz	Dec. 31, 2011 Palmarejo gold production royalty [Member]	Jan. 21, 2009 Palmarejo gold production royalty [Member]	Sep. 30, 2012 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Sep. 30, 2011 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Sep. 30, 2012 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Sep. 30, 2011 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Dec. 31, 2011 Forward foreign exchange contracts [Member] Mexican peso forward purchase contracts [Member] USD ($)	Sep. 30, 2012 Silver [Member] Cerro Bayo Mine [Member] USD ($)	Sep. 30, 2012 Commodity [Member] USD ($)	Sep. 30, 2011 Commodity [Member] USD ($)	Sep. 30, 2012 Commodity [Member] USD ($)	Sep. 30, 2011 Commodity [Member] USD ($)	Dec. 31, 2011 Commodity [Member] USD ($)	Sep. 30, 2012 Derivative Instruments Settle in Year 2011 [Member] MXN	Dec. 31, 2011 Derivative Instruments Settle in Year 2011 [Member] MXN	Sep. 30, 2012 Kensington Term Facility [Member] USD ($)	Sep. 30, 2012 Kensington Term Facility [Member] USD ($)	Dec. 31, 2011 Kensington Term Facility [Member] USD ($)	Sep. 30, 2012 Kensington Term Facility [Member] Call Option [Member] oz	Dec. 31, 2011 Kensington Term Facility [Member] Call Option [Member] oz	Sep. 30, 2012 Kensington Term Facility [Member] Put Option [Member] oz	Dec. 31, 2011 Kensington Term Facility [Member] Put Option [Member] oz	Sep. 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																		209,853
Fair Value Assumptions, Risk Free Interest Rate	4.88%	5.70%
Derivative, Average Forward Price																		1,793	1,611
Fair value liability of the embedded derivative									170,200,000		170,200,000		159,400,000
Company recognized Mark to Market loss									23,400,000	14,500,000	10,800,000	17,400,000
Realized losses on settlement of the liabilities									10,900,000	11,900,000	35,000,000	29,100,000
Weighted average exchange rate of MXP																																13.19	12.40
Foreign exchange contracts of MXP																					17,400,000		17,400,000		25,500,000
Fair value of foreign exchange contracts																					200,000		200,000		(3,200,000)
Mark-to-market gains and losses on forward foreign exchange contract																					600,000	4,100,000	3,400,000	3,800,000
Mark-to-market Realized gains on forward foreign exchange contract																					400,000	(100,000)	1,500,000	1,000,000
Gold under collars protection																																					104,000	136,000	139,000	190,000
Weighted Average Put Feature of Each Collar																																		962.42	923.34	951.93
Weighted Average Call Feature of Each Collar																																		1,970.05		1,919.83
Contract expiration date			4 years
Notional ounces															7,000	51,000
Derivative fair value of derivative liability																											17,900,000		17,900,000		16,800,000
Realized loss from transaction																	700,000
Average strike price														2,000.00
Unrealized gain																											3,600,000	19,900,000	1,100,000	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				100,000	800,000	100,000	400,000
Fair value of the contract	1,440,000			1,400,000		1,400,000		2,300,000																		20,900,000
Derivative Financial Instruments and Fair Value of Financial Instruments (Textual) [Abstract]
Outstanding provisionally priced sales consists of silver	500,000	200,000
Outstanding provisionally priced sales consists of Gold	3,734	9,701
Outstanding provisionally priced sales	22,100,000	22,500,000
Fair value of gold and silver including embedded derivative		$ 21,700,000