Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 8,415	$ (1,422)
Other comprehensive income (loss):
Change in unrealized gain on available-for-sale securities	(29)
Foreign currency translation adjustments	251	(1,204)
Other comprehensive income (loss)	222	(1,204)
Comprehensive income (loss)	8,637	(2,626)
Comprehensive income attributable to noncontrolling interests	(127)	(91)
Comprehensive income (loss) attributable to IDT Corporation	$ 8,510	$ (2,717)