Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 4,701	$ 1,123	$ 13,941	$ 84,234
Other comprehensive income (loss):
Change in unrealized gain on available-for-sale securities	63	(3)	448	12
Foreign currency translation adjustments	1,899	1,065	(2,001)	(2,912)
Other comprehensive income (loss)	1,962	1,062	(1,553)	(2,900)
Comprehensive income	6,663	2,185	12,388	81,334
Comprehensive income attributable to noncontrolling interests	(464)	(558)	(1,445)	(1,003)
Comprehensive income attributable to IDT Corporation	$ 6,199	$ 1,627	$ 10,943	$ 80,331