Summary of Significant Accounting Policies (Details Textual) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2011 oz	Dec. 31, 2011 oz m	Dec. 31, 2011 m oz	Dec. 31, 2010 oz	Dec. 31, 2009
Summary of Significant Accounting Policies (Textual) [Abstract]
Minimum Voting control			50.00%
Investments in Equity Method			0.00%
Ownership Interest in equity Method			50.00%
Investments in corporate joint ventures under the equity Method			50.00%
Investments in Cost Method			0.00%
Ownership Interest in Cost Method			20.00%
Third-party smelting and refining costs recorded as a reduction of revenue			$ 17,700,000	$ 8,600,000	$ 6,700,000
Company outstanding provisionally priced sales		22,500,000	22,500,000	35,700,000
Consisting ounces of silver		200,000	200,000	600,000
Consisting ounces of gold		9,701	9,701	12,758
Fair value of embedded derivative		21,700,000	21,700,000	37,400,000
Each one cent per ounce change in realized silver price, revenue would vary (plus or minus)		2,000	2,000	6,000
Each one dollar per ounce change in realized gold price, revenue would vary (plus or minus)		9,700	9,700	12,800
Gold lease facility amounting					6,000,000
Maturity of cash and cash equivalents include all highly-liquid investments			Three months or less at the date of purchase
Reported ore on the leach pads, total assets		33,900,000	33,900,000	18,000,000
Reported ore on the leach pads, current assets		27,252,000	27,252,000	7,959,000
Reported ore on the leach pads, non-current assets		6,700,000	6,700,000	10,000,000
Increase in estimated silver ounces inventory	700,000
Decrease in estimated silver ounces inventory	298	200,000
Decrease in estimated gold ounces inventory		10,828
Drilling and related costs		7,200,000	7,200,000	3,700,000
Continued suspension of mining operations in San Bartolome		4,400	4,400
Maturity Period of Certificates of Deposits			Three months to a year
Certificates of deposit and cash		28,900,000	28,900,000	29,000,000
Accrued interest and penalties		$ 1,600,000	$ 1,600,000
3.25% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Interest rate on notes		3.25%	3.25%
Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of shares of common stock equivalents related to convertible debt			1,059,228	1,296,231	1,514,460
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of shares of common stock equivalents related to convertible debt			4,258	496,291	663,365
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Minimum productive life			7
Maximum productive life			31
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Minimum productive life			3
Maximum productive life			13
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Minimum productive life			3
Maximum productive life			7