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Stockholders' equity (Details) - Schedule of stock options outstanding (USD $)
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12 Months Ended | |||||
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Jul. 31, 2013
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Jul. 31, 2012
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Jul. 31, 2011
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Jul. 31, 2010
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Jul. 31, 2013
Range of Exercise Prices 2.88 [Member]
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Jul. 31, 2013
Range of Exercise Prices 12.99 to 17.66 [Member]
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| Stockholders' equity (Details) - Schedule of stock options outstanding [Line Items] | ||||||
| Shares | 726,645 | 736,490 | 785,124 | 1,132,450 | 336,817 | 389,828 |
| Weighted-Average Remaining Contractual Life in years | 4 years 171 days | 343 days | ||||
| Weighted Average Exercise price (in Dollars per share) | $ 10.39 | $ 14.50 | $ 14.53 | $ 14.30 | $ 2.88 | $ 17.04 |
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- Details
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- Definition
Number of options outstanding, including both vested and non-vested options. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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