Document and Entity Information	3 Months Ended
	Oct. 31, 2012	Dec. 01, 2012 Common Class A [Member]	Dec. 01, 2012 Common Class B [Member]
Class of Stock [Line Items]
Entity Registrant Name	ECOLOGY & ENVIRONMENT INC
Entity Central Index Key	0000809933
Current Fiscal Year End Date	--07-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		2,600,144	1,643,773
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Oct. 31, 2012