Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2015	Oct. 31, 2014
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 4,575	$ 80,354
Other comprehensive income (loss):
Change in unrealized gain on available-for-sale securities	528	7
Foreign currency translation adjustments	111	(1,858)
Other comprehensive income (loss)	639	(1,851)
Comprehensive income	5,214	78,503
Comprehensive income attributable to noncontrolling interests	(382)	(199)
Comprehensive income attributable to IDT Corporation	$ 4,832	$ 78,304