Quarterly report pursuant to Section 13 or 15(d)

Income taxes (Details)

v3.7.0.1
Income taxes (Details)
3 Months Ended 9 Months Ended
Apr. 30, 2017
Apr. 30, 2016
Apr. 30, 2017
Apr. 30, 2016
Income Tax Disclosure [Abstract]        
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent 82.00% 82.00% 4.20% 3.10%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent       34.00%