Accumulated Other Comprehensive Loss (Details) - Schedule of accumulated balances for each classification of other comprehensive (loss) income $ in Thousands	6 Months Ended
	Jan. 31, 2021 USD ($)
Unrealized Gain (Loss) on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 42
Other comprehensive income (loss) attributable to IDT Corporation	17
Ending balance	59
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(7,452)
Other comprehensive income (loss) attributable to IDT Corporation	(1,564)
Ending balance	(9,016)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(7,410)
Other comprehensive income (loss) attributable to IDT Corporation	(1,547)
Ending balance	$ (8,957)