Derivative Financial Instruments and Fair Value of Financial Instruments (Details)										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 ($)	Jun. 30, 2012 2013 [Member]	Jun. 30, 2012 2013 [Member] MXN	Jun. 30, 2012 2014 [Member]	Jun. 30, 2012 2014 [Member] MXN	Jun. 30, 2012 Derivative Instruments Settle in Year 2014 Member [Member]	Jun. 30, 2012 Derivative Instruments Settle in Year 2014 Member [Member] MXN	Jun. 30, 2012 Thereafter [Member]	Jun. 30, 2012 Thereafter [Member] MXN	Jun. 30, 2012 Franco-Nevada warrant [Member] USD ($)	Jun. 30, 2011 Franco-Nevada warrant [Member] USD ($)	Jun. 30, 2012 Franco-Nevada warrant [Member] USD ($)	Jun. 30, 2011 Franco-Nevada warrant [Member] USD ($)	Jun. 30, 2012 Palmarejo gold production royalty [Member] 2013 [Member] USD ($) oz	Jun. 30, 2012 Palmarejo gold production royalty [Member] 2014 [Member] USD ($) oz	Jun. 30, 2012 Palmarejo gold production royalty [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Jun. 30, 2012 Palmarejo gold production royalty [Member] Thereafter [Member] USD ($) oz	Jun. 30, 2012 Mexican peso forward purchase contracts [Member] 2013 [Member] USD ($)	Jun. 30, 2012 Mexican peso forward purchase contracts [Member] 2014 [Member] USD ($)	Jun. 30, 2012 Mexican peso forward purchase contracts [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($)	Jun. 30, 2012 Mexican peso forward purchase contracts [Member] Thereafter [Member] USD ($)	Jun. 30, 2012 Mexican Peso Notional Amount [Member] 2013 [Member] oz	Jun. 30, 2012 Mexican Peso Notional Amount [Member] 2014 [Member] oz	Jun. 30, 2012 Mexican Peso Notional Amount [Member] Derivative Instruments Settle in Year 2014 Member [Member] oz	Jun. 30, 2012 Mexican Peso Notional Amount [Member] Thereafter [Member] oz	Jun. 30, 2012 Silver ounces received from Mandalay [Member] 2013 [Member] USD ($) oz	Jun. 30, 2012 Silver ounces received from Mandalay [Member] 2014 [Member] USD ($) oz	Jun. 30, 2012 Silver ounces received from Mandalay [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Jun. 30, 2012 Silver ounces received from Mandalay [Member] Thereafter [Member] USD ($) oz	Jun. 30, 2012 Silver concentrate sales agreements [Member] 2013 [Member] USD ($) oz	Jun. 30, 2012 Silver concentrate sales agreements [Member] 2014 [Member] USD ($) oz	Jun. 30, 2012 Silver concentrate sales agreements [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Jun. 30, 2012 Silver concentrate sales agreements [Member] Thereafter [Member] USD ($) oz	Jun. 30, 2012 Gold concentrates sales agreements [Member] 2013 [Member] USD ($) oz	Jun. 30, 2012 Gold concentrates sales agreements [Member] 2014 [Member] USD ($) oz	Jun. 30, 2012 Gold concentrates sales agreements [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Jun. 30, 2012 Gold concentrates sales agreements [Member] Thereafter [Member] USD ($) oz	Jun. 30, 2012 Gold put options purchased [Member] 2013 [Member] USD ($) oz	Jun. 30, 2012 Gold put options purchased [Member] 2014 [Member] USD ($) oz	Jun. 30, 2012 Gold put options purchased [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Jun. 30, 2012 Gold put options purchased [Member] Thereafter [Member] USD ($) oz	Jun. 30, 2011 Gold call options sold [Member]	Jun. 30, 2012 Gold call options sold [Member] 2013 [Member] USD ($) oz	Jun. 30, 2012 Gold call options sold [Member] 2014 [Member] USD ($) oz	Jun. 30, 2012 Gold call options sold [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Jun. 30, 2012 Gold call options sold [Member] Thereafter [Member] USD ($) oz	Jun. 30, 2012 Foreign Exchange Forward [Member] Mexican peso forward purchase contracts [Member] USD ($)	Jun. 30, 2011 Foreign Exchange Forward [Member] Mexican peso forward purchase contracts [Member] USD ($)	Jun. 30, 2012 Foreign Exchange Forward [Member] Mexican peso forward purchase contracts [Member] USD ($)	Jun. 30, 2011 Foreign Exchange Forward [Member] Mexican peso forward purchase contracts [Member] USD ($)	Jun. 30, 2012 Line of Credit [Member] USD ($)	Jun. 30, 2012 Line of Credit [Member] USD ($)	Dec. 31, 2011 Line of Credit [Member] USD ($)
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net																																															$ 100,000	$ (700,000)	$ 2,800,000	$ 300,000
Derivative Instruments, Loss Recognized in Income										11,000,000	9,700,000	24,200,000	17,200,000
Derivative instruments Settlement
Derivative, Notional Amount														15,514,000	25,097,000	24,895,000	46,099,000									1,152,000	0	0	0	11,184,000	0	0	0	9,058,000	0	0	0	1,440,000	1,800,000	720,000	0		0	0	720,000	0
Derivative average gold price in excess of minimum contractual Deduction Rate	400													501,000	502,000	498,000	492,000
Fair value of foreign exchange contracts																		17,400,000	8,700,000	0	0
Average rate (MXP/$)			13.29		13.52		0		0
Average forward price																										18.43	0	0	0
Derivative average price																										28.85	0	0	0					1,590	0	0	0
Average strike price		2,000	2,000	2,000	2,000	1,934	1,934	2,000	2,000																													923	928	979	1,010	1,737.68
Notional ounces														30,977	50,004	50,004	93,725					231,319	117,628,000	0	0	62,500	0	0	0	387,614	0	0	0	5,698	0	0	0	34,000	45,000	47,000	30,000		14,000	20,000	47,000	30,000
Derivative Instruments, Gain (Loss) Recognized in Income, Net																																															(1,200,000)	900,000	(1,900,000)	1,100,000
Weighted Average Put Feature of Each Collar																																																			$ 958.16	$ 923.34	$ 951.93