Contract Receivables, net, Allowance for Doubtful Accounts and Contract Adjustments (Details) - USD ($) $ in Thousands		12 Months Ended
		Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period		$ 5,954	$ 6,508	$ 5,969
Net increase (decrease) due to adjustments in the allowance for contract adjustments	[1]	(577)	(263)	474
Net increase (decrease) due to adjustments in the allowance for doubtful accounts	[2]	552	(291)	95
Transfer of reserves (to) from allowance for project disallowances	[3]	0	0	(30)
Balance at end of period		5,929	5,954	6,508
Allowance for doubtful accounts		5,954	5,954	$ 6,508
Brazil [Member]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period		400
Balance at end of period		800	400
Allowance for doubtful accounts		$ 400	$ 400

[1] Increases (decreases) to the allowance for contract adjustments on the consolidated balance sheets are recorded as (decreases) increases to revenue on the consolidated statements of operations.

[2] Increases (decreases) to the allowance for doubtful accounts on the consolidated balance sheets are recorded as increases (decreases) to administrative and other indirect operating expenses on the consolidated statements of operations.

[3] The allowance for project disallowances is included in other accrued liabilities on the consolidated balance sheets. Refer to Note 12 of these consolidated financial statements.