Common stock options granted, forfeited or expired and exercised - Stock-Based Compensation (Details 1) (USD $)	12 Months Ended
Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options Outstanding	29,701,197	7,340,182	7,465,638
Options Granted	24,532,719	5,851,696	3,300,000
Options Forfeited or expired	(630,778)	(912,250)	(2,848,704)
Options Exercised	(5,180,378)	(1,299,994)	(576,752)	0
Options Outstanding	29,701,197	29,701,197	7,340,182	7,465,638
Options Exercisable	29,641,197
Weighted Average Exercise Price per Share	$ 0.08	$ 0.46	$ 0.49
Weighted Average Exercise Price per Share, Granted	$ 0.001	$ 0.001	$ 0.28
Weighted Average Exercise Price per Share, Forfeited or expired	$ 0.75	$ 0.65	$ 0.41
Weighted Average Exercise Price per Share, Exercised	$ 0.001	$ 0.001	$ 0.001
Weighted Average Exercise Price per Share, Outstanding		$ 0.08	$ 0.46	$ 0.49
Weighted Average Exercise Price per Share, Exercisable	$ 0.08

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iii)

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

+ References

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

-Publisher FASB

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-Topic 718

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-Subparagraph (c)(1)(iv)(3)-(4)

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Weighted average price of options that were either forfeited or expired.

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-Publisher FASB

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- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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No definition available.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

+ References

No definition available.

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Number of share options (or share units) exercised during the current period.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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