Debt and Royalty Obligation (Details Textual) (USD $)	1 Months Ended		3 Months Ended	12 Months Ended								12 Months Ended		3 Months Ended	12 Months Ended							10 Months Ended	12 Months Ended			12 Months Ended
	Sep. 30, 2010	Jan. 31, 2009	Mar. 31, 2010	Dec. 31, 2011 oz	Dec. 31, 2010 oz	Dec. 31, 2009	Jun. 01, 2011	Dec. 20, 2010	Jul. 06, 2010	Jul. 15, 2009	Jan. 21, 2009	Dec. 31, 2011 Maximum	Dec. 31, 2011 Minimum	Sep. 30, 2010 3.25% Convertible Senior Notes due March 2028 [Member]	Dec. 31, 2011 3.25% Convertible Senior Notes due March 2028 [Member]	Dec. 31, 2010 3.25% Convertible Senior Notes due March 2028 [Member]	Mar. 18, 2008 3.25% Convertible Senior Notes due March 2028 [Member]	Dec. 31, 2011 1.25% Convertible Senior Notes due January 2024 [Member]	Jan. 21, 2011 1.25% Convertible Senior Notes due January 2024 [Member]	Jan. 18, 2011 1.25% Convertible Senior Notes due January 2024 [Member]	Dec. 31, 2010 1.25% Convertible Senior Notes due January 2024 [Member]	Oct. 31, 2011 Senior Term Notes due December 2012 [Member]	Dec. 31, 2011 Senior Term Notes due December 2012 [Member]	Dec. 31, 2010 Senior Term Notes due December 2012 [Member]	Feb. 05, 2010 Senior Term Notes due December 2012 [Member]	Dec. 31, 2011 Kensington Term Facility [Member] oz	Dec. 31, 2010 Kensington Term Facility [Member] oz	Oct. 27, 2009 Kensington Term Facility [Member]	Dec. 31, 2011 Kensington Term Facility [Member] Call Option [Member] oz	Dec. 31, 2011 Kensington Term Facility [Member] Put Option [Member] oz	Dec. 31, 2011 Coeur Mexicana [Member]	Dec. 31, 2011 Empresa Minera Manquiri [Member]	Dec. 31, 2010 Empresa Minera Manquiri [Member]	Nov. 27, 2009 Empresa Minera Manquiri [Member]
Debt and capital lease obligations (Textual) [Abstract]
Debt Instrument, Face Amount															$ 48,700,000		$ 230,000,000								$ 100,000,000									$ 5,000,000
Interest rate on notes															3.25%			1.25%					6.50%											6.50%
Outstanding balance				427,567,000														0					0			75,800,000						0	2,500,000
Initial conversion rate of Convertible Senior Notes															17.60254 shares of the Company’s common stock per $1,000 principal amount of notes, which is equivalent to an initial conversion price of approximately $56.81 per share $56.81 per share
Percentage of principal amount of notes to be repurchased plus accrued and unpaid interest equivalent to repurchase price															100.00%
Initial conversion rate of common stock per $1,000 principal amount of notes															17.60254
Per principal amount of notes convertible into specified number of common stock															1,000
Initial conversion price, per share															$ 56.81
Repurchase convertible senior notes																$99.7 million of the 3.25% Convertible Senior Notes due 2028 were repurchased in exchange for 6.5 million shares of the Company’s common stock which reduced the principal amount of the notes outstanding to $48.7 million ($43.2 million net of debt discount)
Reduced to principal amount of the notes outstanding																43.2
Long-term debt (Note 12)				115,861,000	130,067,000										45,545,000	43,220,000		0			0		0	15,000,000		60,424,000	48,322,000
Fair value of the notes outstanding															49,200,000	48,200,000
Carrying value of the equity component															10,900,000	10,900,000
Interest on notes														2,400,000	1,600,000								1,300,000	3,300,000
Accretion expense				21,550,000	19,018,000	14,209,000								3,000,000	2,300,000
Debt discount				(74,607,000)											3,100,000
Effective interest rate on the notes															8.90%
Principal amount of notes repurchased																			914,000	945,000				36,700,000
Amount paid to repurchase Notes																								43,400,000
Issued common stock value				897,000	893,000
Interest on notes				3,800,000	1,700,000
Weighted average share price				90.00%
Notes repurchased															0	99,700,000							11,300,000	57,500,000
Repurchase Of Notes Principle Amount																						18,750,000
Notes repurchased																						22,200,000
Gain (loss) on debt extinguishments				(5,526,000)	(20,300,000)	31,528,000																	5,500,000	10,000,000
Common stock issued in exchange of notes																							297,455
Common stock issued in exchange of notes				0												6,500,000								1,060,413
Issued common stock value																							4,200,000
Borrowing under term facility								100,000,000																				45,000,000
Interest rate in excess of LIBOR				4.50%
Protection of gold under gold hedging program																										243,750
Gold under collars protection																											182,500		136,000	190,000
Weighted average put feature of each collar					911.99																					951.93
Weighted average call feature of each collar					1,795.18																					1,919.83
Debt equity ratio												0.40
Project cash flow to debt service ratio													1.25
Maximum tangible net worth of borrower				325,000,000
Maximum tangible net worth of guarantor				1,000,000,000
Gold leased from MIC				0	10,000
Outstanding amount of capital leases					28,400,000																										18,300,000
Additional Long term debt and capital lease obligations(Textual) [Abstract]
Date of first installment			March 31,2010
Short-term Financing Agreement									2,400,000
Capital leases for equipment and facilities leases				7,700,000	10,800,000
Interest to finance insurance premium									2.90%
Final payment of monthly installments							200,000
Outstanding Amount				0	1,100,000
Equipment financing agreement bearing interest										8.26%
Final payment made on loan, monthly installments										24 months
Equipment Financing Agreement Outstanding				100,000	1,200,000
Purchased royalty											50.00%
Royalty consideration received		78,000,000
Royalty Revenue in Cash											75,000,000
Value of warrant received as royalty consideration											3,000,000
Warrant exercised and related stock sold	10,000,000
Payments on gold production royalty				(73,191,000)	(43,125,000)	(15,762,000)
Royalty agreement minimum obligation for the period				400,000	400,000
Royalty agreement minimum obligation for per month				4,167 ounces per month	4,167 ounces per month
Royalty agreement period				8 years	8 years
Percentage of actual gold production				50.00%
Monthly average market price of gold per ounce				400
Percentage of inflation rate				1.00%
Payment of royalty on a total of ounces of gold				143,354
Additional payment of royalty on ounces of gold				256,646
Implicit interest rate				29.30%
Accretion expense on royalty obligation discount				22,200,000	20,500,000
Remaining minimum obligation under royalty agreements				72,100,000	80,300,000
Expensed Interest				34,774,000	30,942,000	18,102,000
Capitalized interest				$ 2,175,000	$ 9,885,000	$ 22,825,000
Percentage Royalty Obligation Payment Due to Affiliates				50.00%