Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Consolidated Statements of Operations [Abstract]
Revenue, net	$ 104,502	$ 105,817	$ 126,935
Cost of professional services and other direct operating expenses	38,334	38,912	47,500
Subcontract costs	18,379	18,550	23,327
Administrative and indirect operating expenses	30,576	31,769	35,604
Marketing and related costs	10,245	11,301	11,433
Depreciation and amortization	1,040	1,143	1,467
Income from operations	5,928	4,142	7,604
Interest income (expense)	17	(73)	(31)
Proxy contest costs, net	(375)	0	0
Net foreign exchange (loss) gain	(91)	44	134
Other (expense) income	(54)	(104)	262
Gain on insurance settlement	0	358	0
Income before income tax provision	5,425	4,367	7,969
Income tax provision	2,472	3,759	3,769
Net income	2,953	608	4,200
Net loss (income) attributable to the noncontrolling interest	62	278	(804)
Net income attributable to Ecology and Environment, Inc.	$ 3,015	$ 886	$ 3,396
Net income per common share: basic and diluted (in dollars per share)	$ 0.70	$ 0.21	$ 0.79
Weighted average common shares outstanding - basic and diluted (in shares)	4,294,501	4,289,993	4,287,775