Supplemental disclosure for statement of cash flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017
Supplemental disclosure for statement of cash flows (Details) [Line Items]
Income Taxes Paid	$ 15	$ 996
Interest Paid	45	77
Installment Loans Financed Amount	0	69
Capital Lease Obligation Cost Basis	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in Shares)	569,602
Officer [Member]
Supplemental disclosure for statement of cash flows (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in Shares)	340,898
Treasury Stock, Shares, Acquired (in Shares)	106,911
Treasury Stock, Value, Acquired, Cost Method	$ 1,014