Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 199,397		$ 106,830		$ 199,397		$ 106,830		$ 151,883	$ 175,012	$ 64,427	$ 66,118
Short term investments	907				907					20,254
Other assets	113,454				113,454					106,045
Sales Revenue, Goods, Net	254,406		231,090		458,970		430,714
Cost of Goods Sold	(131,823)		(77,102)		(224,377)		(169,576)
Depreciation, depletion and amortization	(61,024)		(57,641)		(113,616)		(107,682)
Gross Profit	61,559		96,347		120,977		153,456
Costs of Metals Sold	6,305		4,077		12,872		6,839
Loss on impairment	4,813		0		4,813		0
Operating Income (Loss)	41,574		79,339		85,761		117,881
Interest and other income	(3,221)		2,763		1,786		4,664
Interest expense	(7,557)		(9,268)		(14,227)		(18,573)
Gains (Losses) on Extinguishment of Debt	0		(389)		0		(856)
Gain (Loss) on Derivative Instruments, Net, Pretax	16,039		(12,432)		(7,074)		(17,700)
Income tax benefit (expense)	(23,862)		(21,402)		(39,298)		(34,341)
Net Income (Loss) Attributable to Parent	22,973		38,611		26,948		51,075
Assets	3,233,510				3,233,510					3,264,441
Payments to Acquire Productive Assets	32,238		25,764		63,885		41,681
Palmarejo [Member]
Assets
Sales Revenue, Goods, Net	136,365		123,727		260,087		211,892
Cost of Goods Sold	(62,538)		(37,770)		(108,397)		(75,139)
Depreciation, depletion and amortization	(42,748)		(41,753)		(80,517)		(75,428)
Gross Profit	31,079		44,204		71,173		61,325
Costs of Metals Sold	1,624		1,276		2,945		1,912
Loss on impairment					0
Other General Expense	0		0		0		0
Operating Income (Loss)	29,455		42,928		68,228		59,413
Interest and other income	(4,720)		539		(139)		1,828
Interest expense	(5,672)		(6,112)		(10,481)		(11,815)
Gains (Losses) on Extinguishment of Debt			0				0
Gain (Loss) on Derivative Instruments, Net, Pretax	14,105		(13,731)		(11,505)		(20,041)
Income tax benefit (expense)	(11,967)		(6,286)		(15,511)		(10,062)
Net Income (Loss) Attributable to Parent	21,201		17,338		30,592		19,323
Assets	1,954,084	[1]	2,095,411	[1]	1,954,084	[1]	2,095,411	[1]
Payments to Acquire Productive Assets	11,174	[2]	10,278	[2]	18,344	[2]	15,359	[2]
Reportable Segment [Member]
Assets
Total assets for reportable segments	2,919,752				2,919,752					2,963,130
Sales Revenue, Goods, Net	254,406		231,090		458,970		430,714
Cost of Goods Sold	(131,823)		(77,102)		(224,377)		(169,576)
Depreciation, depletion and amortization	(61,024)		(57,641)		(113,616)		(107,682)
Gross Profit	61,559		96,347		120,977		153,456
Costs of Metals Sold	6,305		4,077		12,872		6,839
Loss on impairment					4,813
Other General Expense	8,867		12,931		17,531		28,736
Operating Income (Loss)	41,574		79,339		85,761		117,881
Interest and other income	(3,221)		2,763		1,786		4,664
Interest expense	(7,557)		(9,268)		(14,227)		(18,573)
Gains (Losses) on Extinguishment of Debt			(389)				(856)
Gain (Loss) on Derivative Instruments, Net, Pretax	16,039		(12,432)		(7,074)		(17,700)
Income tax benefit (expense)	(23,862)		(21,402)		(39,298)		(34,341)
Net Income (Loss) Attributable to Parent	22,973		38,611		26,948		51,075
Assets	2,919,752	[1]	2,984,289	[1]	2,919,752	[1]	2,984,289	[1]
Payments to Acquire Productive Assets	32,238	[2]	25,764	[2]	63,885	[2]	41,681	[2]
San Bartolome [Member]
Assets
Sales Revenue, Goods, Net	53,383		55,598		94,759		101,919
Cost of Goods Sold	(22,773)		(14,126)		(36,381)		(28,244)
Depreciation, depletion and amortization	(4,070)		(5,182)		(8,289)		(10,325)
Gross Profit	26,540		36,290		50,089		63,350
Costs of Metals Sold	(70)		31		0		35
Loss on impairment					0
Other General Expense	25		70		30		108
Operating Income (Loss)	26,585		36,189		50,059		63,207
Interest and other income	631		180		726		787
Interest expense	(36)		(2)		(36)		(36)
Gains (Losses) on Extinguishment of Debt			0				0
Gain (Loss) on Derivative Instruments, Net, Pretax	0		0		0		0
Income tax benefit (expense)	(10,889)		(12,109)		(18,578)		(22,146)
Net Income (Loss) Attributable to Parent	16,291		24,258		32,171		41,812
Assets	289,428	[1]	269,439	[1]	289,428	[1]	269,439	[1]
Payments to Acquire Productive Assets	7,800	[2]	3,276	[2]	18,007	[2]	6,812	[2]
Kensington [Member]
Assets
Sales Revenue, Goods, Net	21,124		26,012		31,500		74,122
Cost of Goods Sold	(16,106)		(12,844)		(33,197)		(45,764)
Depreciation, depletion and amortization	(9,719)		(9,890)		(16,324)		(19,255)
Gross Profit	(4,701)		3,278		(18,021)		9,103
Costs of Metals Sold	274		320		496		366
Loss on impairment					0
Other General Expense	16		116		35		136
Operating Income (Loss)	(4,991)		2,842		(18,552)		8,601
Interest and other income	0		2		0		3
Interest expense	(901)		(1,360)		(1,793)		(2,607)
Gains (Losses) on Extinguishment of Debt			0				0
Gain (Loss) on Derivative Instruments, Net, Pretax	2,187		2,374		1,636		1,676
Income tax benefit (expense)	0		0		0		(20)
Net Income (Loss) Attributable to Parent	(3,705)		3,858		(18,709)		7,653
Assets	518,611	[1]	507,531	[1]	518,611	[1]	507,531	[1]
Payments to Acquire Productive Assets	9,324	[2]	7,365	[2]	20,202	[2]	12,734	[2]
Rochester [Member]
Assets
Sales Revenue, Goods, Net	34,153		14,434		52,911		28,696
Cost of Goods Sold	(20,751)		(5,341)		(30,317)		(12,698)
Depreciation, depletion and amortization	(2,060)		(584)		(3,702)		(1,098)
Gross Profit	11,342		8,509		18,892		14,900
Costs of Metals Sold	1,135		340		1,844		362
Loss on impairment					0
Other General Expense	692		11,025		2,033		14,561
Operating Income (Loss)	9,515		(2,856)		15,015		(23)
Interest and other income	239		5		288		51
Interest expense	(7)		0		(15)		0
Gains (Losses) on Extinguishment of Debt			0				0
Gain (Loss) on Derivative Instruments, Net, Pretax	0		0		0		0
Income tax benefit (expense)	0		0		0		0
Net Income (Loss) Attributable to Parent	9,747		(2,851)		15,288		28
Assets	94,677	[1]	35,606	[1]	94,677	[1]	35,606	[1]
Payments to Acquire Productive Assets	2,946	[2]	4,201	[2]	5,585	[2]	5,869	[2]
Martha [Member]
Assets
Sales Revenue, Goods, Net	4,149		4,769		7,767		4,455
Cost of Goods Sold	(7,102)		(3,749)		(10,795)		(3,359)
Depreciation, depletion and amortization	(704)		747		(1,300)		155
Gross Profit	(3,657)		1,767		(4,328)		1,251
Costs of Metals Sold	2,763		1,527		6,174		2,823
Loss on impairment					4,813
Other General Expense	81		0		279		0
Operating Income (Loss)	(11,314)		240		(15,594)		(1,572)
Interest and other income	(494)		(179)		(570)		(489)
Interest expense	(1)		(68)		(1)		(413)
Gains (Losses) on Extinguishment of Debt			0				0
Gain (Loss) on Derivative Instruments, Net, Pretax	0		0		0		0
Income tax benefit (expense)	(28)		(410)		(239)		(369)
Net Income (Loss) Attributable to Parent	(11,837)		(417)		(16,404)		(2,843)
Assets	13,070	[1]	19,341	[1]	13,070	[1]	19,341	[1]
Payments to Acquire Productive Assets	529	[2]	573	[2]	1,188	[2]	824	[2]
Endeavor [Member]
Assets
Sales Revenue, Goods, Net	5,232		6,550		11,946		9,630
Cost of Goods Sold	(2,553)		(3,272)		(5,290)		(4,372)
Depreciation, depletion and amortization	(1,592)		(865)		(3,236)		(1,484)
Gross Profit	1,087		2,413		3,420		3,774
Costs of Metals Sold	0		0		0		0
Loss on impairment					0
Other General Expense	0		0		0		0
Operating Income (Loss)	1,087		2,413		3,420		3,774
Interest and other income	0		0		0		0
Interest expense	0		0		0		0
Gains (Losses) on Extinguishment of Debt			0				0
Gain (Loss) on Derivative Instruments, Net, Pretax	0		0		0		0
Income tax benefit (expense)	0		(3)		0		(3)
Net Income (Loss) Attributable to Parent	1,087		2,410		3,420		3,771
Assets	33,228	[1]	40,760	[1]	33,228	[1]	40,760	[1]
Payments to Acquire Productive Assets	0	[2]	0	[2]	0	[2]	0	[2]
Other Mining Properties [Member]
Assets
Sales Revenue, Goods, Net	0		0		0		0
Cost of Goods Sold	0		0		0		0
Depreciation, depletion and amortization	(131)		(114)		(248)		(247)
Gross Profit	(131)		(114)		(248)		(247)
Costs of Metals Sold	579		583		1,413		1,341
Loss on impairment					0
Other General Expense	8,053		1,720		15,154		13,931
Operating Income (Loss)	(8,763)		(2,417)		(16,815)		(15,519)
Interest and other income	1,123		2,216		1,481		2,484
Interest expense	(940)		(1,726)		(1,901)		(3,702)
Gains (Losses) on Extinguishment of Debt			(389)				(856)
Gain (Loss) on Derivative Instruments, Net, Pretax	(253)		(1,075)		2,795		665
Income tax benefit (expense)	(978)		(2,594)		(4,970)		(1,741)
Net Income (Loss) Attributable to Parent	(9,811)		(5,985)		(19,410)		(18,669)
Assets	16,654	[1]	16,201	[1]	16,654	[1]	16,201	[1]
Payments to Acquire Productive Assets	$ 465	[2]	$ 71	[2]	$ 559	[2]	$ 83	[2]

[1] Segment assets consist of receivables, prepaids, inventories, property, plant and equipment, and mining properties

[2] Balance represents cash flow amounts