IDT Financial Services Holding Limited Assets and Liabilities Held for Sale (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016
IDT Financial Services Holding Limited Assets and Liabilities Held for Sale (Textual)
Allowance for doubtful accounts	$ 2,550	$ 861
Net asset value	14,000
Property, plant and equipment, net of accumulated depreciation	228	213
Other intangibles, net of accumulated amortization	57	$ 37
IDT Financial Services Holding Limited [Member]
IDT Financial Services Holding Limited Assets and Liabilities Held for Sale (Textual)
Outstanding equity interests	$ 3,800