Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Consolidated Statements of Comprehensive Income [Abstract]
Net (loss) income including noncontrolling interests	$ (104)	$ 2,511	$ 154
Foreign currency translation adjustments	(85)	174	(607)
Unrealized investment (losses) gains, net	(20)	(18)	21
Comprehensive (loss) income	(209)	2,667	(432)
Comprehensive (income) loss attributable to noncontrolling interests	(189)	290	753
Comprehensive (loss) income attributable to Ecology and Environment Inc.	$ (398)	$ 2,957	$ 321