Earnings Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Apr. 30, 2016	May 02, 2015	Apr. 30, 2016	May 02, 2015
Earnings Per Share [Abstract]
Net income attributable to Ecology and Environment, Inc.	$ 174,603	$ 1,794,176	$ 357,374	$ 2,489,005
Dividends declared	0	0	(1,033,753)	(1,033,071)
Balance at end of period	$ 174,603	$ 1,794,176	$ (676,379)	$ 1,455,934
Weighted-average common shares outstanding (basic and diluted) (in shares)	4,290,720	4,287,460	4,290,106	4,288,067
Distributed earnings per share (in dollars per share)	$ 0	$ 0	$ 0.24	$ 0.24
Undistributed earnings per share (in dollars per share)	0.04	0.42	(0.16)	0.34
Total income per common share (in dollars per share)	$ 0.04	$ 0.42	$ 0.08	$ 0.58
Minimum percentage right of Class B common stock holders to elect Board of Directors			75.00%