Document and Entity Information	3 Months Ended
	Aug. 31, 2011	Sep. 30, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	ELECTRO RENT CORP
Entity Central Index Key	0000032166
Document Type	10-Q
Document Period End Date	Aug. 31, 2011
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--05-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		23,980,581