Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2015	Jul. 31, 2015
Commitments and Contingencies (Textual)
Purchase commitment of company	$ 2,300
Letters of credit outstanding	400
Performance bonds outstanding	12,900
Customer deposits	78,189	$ 84,454
IDT Payment Services and IDT Financial Services [Member]
Commitments and Contingencies (Textual)
Restricted cash and cash equivalents	$ 11,800	$ 7,500
Expire on October 31, 2016 [Member]
Commitments and Contingencies (Textual)
Letters of credit expiration date	Oct. 31, 2016