Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 1,123us-gaap_ProfitLoss	$ 5,599us-gaap_ProfitLoss	$ 84,234us-gaap_ProfitLoss	$ 12,622us-gaap_ProfitLoss
Other comprehensive income (loss):
Change in unrealized gain on available-for-sale securities	(3)		12
Foreign currency translation adjustments	1,065	531	(2,912)	1,713
Other comprehensive income (loss)	1,062	531	(2,900)	1,713
Comprehensive income	2,185	6,130	81,334	14,335
Comprehensive income attributable to noncontrolling interests	(558)	(582)	(1,003)	(1,548)
Comprehensive income attributable to IDT Corporation	$ 1,627us-gaap_ComprehensiveIncomeNetOfTax	$ 5,548us-gaap_ComprehensiveIncomeNetOfTax	$ 80,331us-gaap_ComprehensiveIncomeNetOfTax	$ 12,787us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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