Document and Entity Information	3 Months Ended
	Oct. 31, 2011	Dec. 08, 2011 Class A Common Stock	Dec. 08, 2011 Class B Common Stock
Entity Registrant Name	IDT CORP
Entity Central Index Key	0001005731
Amendment Flag	false
Current Fiscal Year End Date	--07-31
Document Type	10-Q
Document Period End Date	Oct. 31, 2011
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		1,574,326	21,168,970