Other Operating Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Other Operating Expense [Abstract]
Corporate-Straight Path Communications Inc. class action legal fees net of insurance proceeds	$ (160)	$ (330)	$ (421)	$ (525)
net2phone-indemnification claim and other, net	(169)		(534)
net2phone—other, net	(63)	25	(63)	25
Telecom & Payment Services-accrual for non-income related taxes related to a foreign subsidiary		(2,000)	(2,150)	(3,100)
Telecom & Payment Services-gain on sale of calling card business in Asia		215		215
Total other operating expense, net	$ (392)	$ (2,090)	$ (3,168)	$ (3,385)