Commitments and Contingencies (Details)	9 Months Ended
	Apr. 30, 2014 City of Denver [Member] USD ($)	Apr. 30, 2014 Walsh Environmental Scientists and Engineers [Member] USD ($)	Apr. 30, 2014 Pending Litigation [Member] Ecology and Environment do Brasil LTDA [Member] USD ($) Employees	Apr. 30, 2014 Pending Litigation [Member] Ecology and Environment do Brasil LTDA [Member] BRL Employees
Loss Contingencies [Line Items]
Penalty	$ 200,000	$ 100,000
Supplemental Environmental Project		100,000
Final Compliance Order and Assessment of Administrative Penalty against Denver			$ 200,000	520,000
Number of employees individually served with Notices of Infraction			4	4