Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Jan. 31, 2016	Jul. 31, 2015
Commitments and Contingencies (Textual)
Purchase commitment of company	$ 1,600
Letters of credit outstanding	300
Performance bonds outstanding	13,100
Customer deposits	85,129	$ 84,454
IDT Payment Services and IDT Financial Services [Member]
Commitments and Contingencies (Textual)
Restricted cash and cash equivalents	$ 9,100	$ 7,500
Expire on January 31, 2017 [Member]
Commitments and Contingencies (Textual)
Letters of credit expiration date	Jan. 31, 2017