Accumulated Other Comprehensive Loss (Details) - Schedule of accumulated balances for each classification of other comprehensive (loss) income $ in Thousands	3 Months Ended
	Oct. 31, 2020 USD ($)
Unrealized Gain (Loss) on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 42
Other comprehensive (loss) income attributable to IDT Corporation	(29)
Ending balance	13
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(7,452)
Other comprehensive (loss) income attributable to IDT Corporation	251
Ending balance	(7,201)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(7,410)
Other comprehensive (loss) income attributable to IDT Corporation	222
Ending balance	$ (7,188)