Segment Reporting (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Financial information relating to reporting segments
Sales of metal	$ 343,575	$ 118,564	$ 774,289	$ 307,871
Production costs applicable to sales	(141,253)	(60,402)	(310,829)	(170,795)
Depreciation, depletion and amortization	(58,652)	(37,801)	(166,334)	(95,503)
Gross profit (loss)	143,670	20,361	297,126	41,573
Exploration expense	4,772	3,840	11,611	9,521
OPERATING INCOME	127,391	10,476	245,272	11,480
Interest income and other	(6,610)	(638)	(1,946)	(2,725)
Interest expense	7,980	9,951	26,553	21,402
Loss on debt extinguishments	(784)	(806)	(1,640)	(12,714)
Fair value adjustments, net	(53,351)	(19,107)	(71,051)	(65,881)
Income tax benefit (provision)	(27,606)	(3,233)	(61,947)	13,137
Income (loss) from continuing operations	31,060	(23,259)	82,135	(78,105)
Loss from discontinued operations, net of income taxes		(251)		(6,029)
Loss on sale of discontinued assets		882		(2,095)
Net income (loss)	31,060	(22,628)	82,135	(86,229)
Segment assets	3,271,219		3,271,219		3,157,527
Capital expenditures	(38,099)	(36,783)	(79,780)	(129,439)
Palmarejo [Member]
Financial information relating to reporting segments
Sales of metal	166,875	61,459	378,767	151,907
Production costs applicable to sales	(64,112)	(31,340)	(139,251)	(92,107)
Depreciation, depletion and amortization	(41,182)	(22,490)	(116,610)	(63,574)
Gross profit (loss)	61,581	7,629	122,906	(3,774)
Exploration expense	2,200	1,282	4,112	3,069
Other operating expenses	(225)	1	(225)	352
OPERATING INCOME	59,156	6,346	118,569	(7,195)
Interest income and other	(6,278)	381	(4,450)	642
Interest expense	5,270	(5,558)	17,085	16,426
Fair value adjustments, net	(26,464)	(18,850)	(46,505)	(55,029)
Income tax benefit (provision)	(2,459)	5,200	(12,521)	12,897
Net income (loss)	18,685	(12,481)	38,008	(65,111)
Segment assets	2,050,108	2,126,953	2,050,108	2,126,953
Capital expenditures	(9,528)	15,809	(24,887)	43,128
Rochester [Member]
Financial information relating to reporting segments
Sales of metal	17,453	5,828	46,149	28,995
Production costs applicable to sales	(11,356)	(2,770)	(24,054)	(14,154)
Depreciation, depletion and amortization	(573)	(445)	(1,671)	(1,368)
Gross profit (loss)	5,524	2,613	20,424	13,473
Exploration expense	242	123	604	164
Other operating expenses	(3,158)	(152)	(17,719)	(925)
OPERATING INCOME	2,124	2,338	2,101	12,384
Interest income and other	7		58	1
Interest expense	(14)		(14)
Net income (loss)	2,117	2,338	2,145	12,385
Segment assets	55,734	30,786	55,734	30,786
Capital expenditures	(13,559)	139	(19,428)	226
San Bartolome [Member]
Financial information relating to reporting segments
Sales of metal	102,820	30,009	204,739	75,876
Production costs applicable to sales	(30,085)	(12,902)	(58,329)	(37,645)
Depreciation, depletion and amortization	(6,067)	(4,943)	(16,392)	(14,152)
Gross profit (loss)	66,668	12,164	130,018	24,079
Exploration expense	61	1	96	1
Other operating expenses	111		219
OPERATING INCOME	66,496	12,163	129,703	24,078
Interest income and other	(227)	(244)	560	(388)
Interest expense	(9)	(92)	(45)	(255)
Income tax benefit (provision)	25,063	6,461	47,209	10,962
Net income (loss)	41,197	5,366	83,009	12,473
Segment assets	265,488	276,150	265,488	276,150
Capital expenditures	(4,418)	806	(11,230)	2,677
Martha [Member]
Financial information relating to reporting segments
Sales of metal	6,037	11,028	10,492	35,235
Production costs applicable to sales	(8,143)	(5,284)	(11,502)	(16,742)
Depreciation, depletion and amortization	(237)	(2,244)	(82)	(7,348)
Gross profit (loss)	(2,343)	3,500	(1,092)	11,145
Exploration expense	1,477	1,437	4,300	3,852
Other operating expenses	(150)		(150)
OPERATING INCOME	(3,970)	2,063	(5,542)	7,293
Interest income and other	(99)	(747)	(588)	(3,697)
Interest expense	(35)	(247)	(448)	(302)
Income tax benefit (provision)	173	(3,504)	542	(5,677)
Net income (loss)	(4,277)	(2,435)	(7,120)	(2,383)
Segment assets	19,537	22,130	19,537	22,130
Capital expenditures	(1,130)		(1,954)	(3)
Endeavor [Member]
Financial information relating to reporting segments
Sales of metal	6,205	1,720	15,835	7,338
Production costs applicable to sales	(3,210)	(685)	(7,582)	(2,726)
Depreciation, depletion and amortization	(914)	(330)	(2,398)	(1,440)
Gross profit (loss)	2,081	705	5,855	3,172
Other operating expenses	1		1
OPERATING INCOME	2,082	705	5,856	3,172
Income tax benefit (provision)	(107)		104
Net income (loss)	2,189	705	5,960	3,172
Segment assets	37,546	39,316	37,546	39,316
Kensington [Member]
Financial information relating to reporting segments
Sales of metal	44,185	8,520	118,307	8,520
Production costs applicable to sales	(24,347)	(7,421)	(70,111)	(7,421)
Depreciation, depletion and amortization	(9,567)	(7,220)	(28,822)	(7,220)
Gross profit (loss)	10,271	(6,121)	19,374	(6,121)
Exploration expense	308	438	674	680
Other operating expenses	(88)	170	(224)	170
OPERATING INCOME	9,875	(6,729)	18,476	(6,971)
Interest income and other	1	(28)	4	(28)
Interest expense	1,115	(899)	3,722	(899)
Fair value adjustments, net	(22,244)	(142)	(20,568)	(6,694)
Income tax benefit (provision)	1	7	(21)	(7)
Net income (loss)	(13,484)	(7,805)	(5,831)	(14,599)
Segment assets	515,335	499,958	515,335	499,958
Capital expenditures	(9,230)	20,022	(21,964)	83,119
Other Mining Properties [Member]
Financial information relating to reporting segments
Depreciation, depletion and amortization	(112)	(129)	(359)	(401)
Gross profit (loss)	(112)	(129)	(359)	(401)
Exploration expense	484	559	1,825	1,755
Other operating expenses	7,776	5,722	21,707	19,125
OPERATING INCOME	(8,372)	(6,410)	(23,891)	(21,281)
Interest income and other	(14)		2,470	745
Interest expense	1,537	(3,155)	5,239	(3,520)
Loss on debt extinguishments	(784)	(806)	(1,640)	(12,714)
Fair value adjustments, net	(4,643)	(115)	(3,978)	(4,158)
Income tax benefit (provision)	(17)	1,539	(1,758)	16,886
Loss from discontinued operations, net of income taxes		(251)		(6,029)
Loss on sale of discontinued assets		882		(2,095)
Net income (loss)	(15,367)	(8,316)	(34,036)	(32,166)
Segment assets	17,693	17,646	17,693	17,646
Capital expenditures	(234)	7	(317)	286
Reportable Segment [Member]
Financial information relating to reporting segments
Sales of metal	343,575		774,289	307,871
Production costs applicable to sales	(141,253)	(60,402)	(310,829)	(170,795)
Depreciation, depletion and amortization	(58,652)	(37,801)	(166,334)	(95,503)
Gross profit (loss)	143,670	20,361	297,126	41,573
Exploration expense	4,772	3,840	11,611	9,521
Other operating expenses	11,507	6,045	40,243	20,572
OPERATING INCOME	127,391	10,476	245,272	11,480
Interest income and other	(6,610)	(638)	(1,946)	(2,725)
Interest expense	7,980	(9,951)	26,553	(21,402)
Loss on debt extinguishments	(784)	(806)	(1,640)	(12,714)
Fair value adjustments, net	(53,351)	(19,107)	(71,051)	(65,881)
Income tax benefit (provision)	(27,606)	(3,233)	(61,947)	13,137
Loss from discontinued operations, net of income taxes		(251)		(6,029)
Net income (loss)	31,060	(22,628)	82,135	(86,229)
Segment assets	2,961,441	3,012,939	2,961,441	3,012,939
Capital expenditures	$ (38,099)	$ (36,783)	$ (79,780)	$ 129,439