Derivative contract settlement description.

No definition available.

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- Definition

Weight of silver for which contract entered to mitigate risk.

+ References

No definition available.

+ Details

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- Definition

Amount of increase in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (a),(c),(d),(e)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

+ Details

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- Details

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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579245-113959

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Period Type:	instant

- Definition

Average fixed price related to the group of price risk swap derivatives.

+ References

No definition available.

+ Details

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- Details

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- Details

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Gain on Silver Fixed Price Swap - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended	1 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Oct. 31, 2013 oz	Nov. 30, 2013 oz	Sep. 30, 2014 Contract
Fixed Price Swap Hedge [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of contracts entered					2
Weight of troy ounce difference multiplied description		If the average silver price was less than the fixed price, we would receive the difference multiplied by the 250,000 troy ounces. If the average silver price was greater than the fixed price, we would owe the difference multiplied by the 250,000 troy ounces.
Combined gain from contract	$ 1,206,350
Fixed Price Swap First Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weight of troy ounce for first contract			250,000
Weight of troy ounce for first contract price per share			24.40
Fixed Price Swap Second Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weight of troy ounce for first contract				250,000
Weight of troy ounce for first contract price per share				23.10