Quarterly report pursuant to Section 13 or 15(d)

Net income (loss) per share (Details)

v3.19.1
Net income (loss) per share (Details) - shares
 3 Months Ended 6 Months Ended
Jan. 31, 2019
Jan. 31, 2018
Jan. 31, 2019
Jan. 31, 2018
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 78,000 719,000 108,000 825,000
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 1,652,000 0 1,491,000 0