Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Consolidated Statements of Operations [Abstract]
Revenue, net	$ 88,510	$ 90,684	$ 96,083
Cost of professional services and other direct operating expenses	34,228	33,855	36,179
Subcontract costs	15,859	17,191	15,975
Selling, general and administrative expenses	38,820	39,257	38,139
Depreciation and amortization	1,022	1,083	994
(Loss) income from operations	(1,419)	(702)	4,796
Equity investment income	346	595	368
Net interest income	237	114	29
Net foreign exchange gain (loss)	4	(11)	(86)
Proxy contest costs, net	0	0	(375)
Other income (expense)	58	158	(54)
(Loss) Income before income tax provision	(774)	154	4,678
Income tax (benefit) provision	(664)	258	2,167
Net income (loss)	(110)	(104)	2,511
Net (income) loss attributable to the noncontrolling interest	(444)	(204)	312
Net (loss) income attributable to Ecology and Environment Inc.	$ (554)	$ (308)	$ 2,823
Net (loss) income per common share: basic and diluted (in dollars per share)	$ (0.13)	$ (0.07)	$ 0.66
Weighted average common shares outstanding: basic and diluted (in shares)	4,316,316	4,304,574	4,294,501