Commitments and Contingencies (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jul. 31, 2015
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash and cash equivalents	$ 88,792	$ 91,035
Cash and Cash Equivalents [Member] | IDT Financial Services customer deposits [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash and cash equivalents	88,335	87,613
Cash and Cash Equivalents [Member] | Related to letters of credit [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash and cash equivalents	272	3,163
Cash and Cash Equivalents [Member] | Other [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash and cash equivalents	$ 185	$ 259