Property, Plant and Equipment (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Payments to Acquire Productive Assets	$ 21,784	$ 29,972	$ 32,238	$ 31,647	$ 40,207	$ 38,099	$ 25,764	$ 15,918	$ 115,641		$ 119,988		$ 155,994
Minimum future lease payments under capital leases
2012	8,323								8,323
2013	2,779								2,779
2014	376								376
2015	223								223
2016	107								107
2017 and thereafter	230								230
Total minimum payments due	12,038								12,038
Less: Amount representing interest	(676)								(676)
Present value of net minimum lease payments	11,362								11,362
Less: Current maturities	(7,902)								(7,902)
Non-current portion	3,460								3,460
Minimum future lease payments under operating leases
2012	5,065								5,065
2013	4,245								4,245
2014	3,848								3,848
2015	546								546
2016	9								9
2017 and thereafter	267								267
Total minimum payments due	13,980								13,980
Palmarejo [Member]
Property, Plant and Equipment [Line Items]
Payments to Acquire Productive Assets									38,456	[1]	36,976	[1]	54,226	[1]
Kensington [Member]
Property, Plant and Equipment [Line Items]
Payments to Acquire Productive Assets									36,994	[1]	34,013	[1]	92,730	[1]
Martha [Member]
Property, Plant and Equipment [Line Items]
Payments to Acquire Productive Assets									1,193	[1]	3,426	[1]	100	[1]
Rochester [Member]
Property, Plant and Equipment [Line Items]
Payments to Acquire Productive Assets									11,794	[1]	27,217	[1]	2,349	[1]
San Bartolome [Member]
Property, Plant and Equipment [Line Items]
Payments to Acquire Productive Assets									25,672	[1]	17,731	[1]	6,159	[1]
Other Mining Properties [Member]
Property, Plant and Equipment [Line Items]
Payments to Acquire Productive Assets									$ 1,532	[1]	$ 625	[1]	$ 430	[1]

[1] Balance represents cash flow amounts