Contract Receivables, net, Contract Receivable Concentrations (Details) - USD ($) $ in Thousands	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contracts Receivable, Gross	$ 40,248	$ 48,820
Allowance for doubtful accounts and contract adjustments	$ 5,929	$ 5,954	$ 6,508	$ 5,969
Contract receivables	12.00%	11.00%
Allowance for doubtful accounts receivables	83.00%	82.00%
United States, Canada and South America [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contracts Receivable, Gross	$ 35,266	$ 43,629
Allowance for doubtful accounts and contract adjustments	1,034	1,043
Middle East and Africa [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contracts Receivable, Gross	4,921	5,067
Allowance for doubtful accounts and contract adjustments	4,895	4,894
Asia [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contracts Receivable, Gross	61	124
Allowance for doubtful accounts and contract adjustments	$ 0	$ 17