Contract Receivables, net, Contract Receivable Concentrations (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jul. 31, 2018
Contract Receivable Concentrations [Abstract]
Contracts Receivables	$ 26,091	$ 26,899
Allowance for Doubtful Accounts	$ 1,004	$ 1,284
Contract receivables	9.00%	13.00%
United States [Member]
Contract Receivable Concentrations [Abstract]
Contracts Receivables	$ 20,211	$ 21,580
Allowance for Doubtful Accounts	489	569
South America [Member]
Contract Receivable Concentrations [Abstract]
Contracts Receivables	5,880	5,319
Allowance for Doubtful Accounts	$ 515	$ 715