Quarterly report pursuant to Section 13 or 15(d)

Net income (loss) per share (Details)

v3.10.0.1
Net income (loss) per share (Details) - shares
 3 Months Ended
Oct. 31, 2018
Oct. 31, 2017
Unvested Restricted Stock [Member] | In the Money Stock Options [Member]    
Net income (loss) per share (Details) [Line Items]    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 135,000 931,000
Outstanding Options [Member] | Out of the Money Stock Options [Member]    
Net income (loss) per share (Details) [Line Items]    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 1,330,000 0