Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2018	Oct. 31, 2017
Consolidated Statements of Operations [Abstract]
Revenues	$ 362,316	$ 393,555
Costs and expenses:
Direct cost of revenues (exclusive of depreciation and amortization)	304,693	336,510
Selling, general and administrative	50,552	50,071
Depreciation and amortization	5,594	5,673
Severance		439
Total costs and expenses	360,839	392,693
Other operating expense	(195)	(779)
Income from operations	1,282	83
Interest income, net	108	362
Other expense, net	(1,349)	(826)
Income (loss) before income taxes	41	(381)
Provision for income taxes	(1,189)	(1,416)
Net loss	(1,148)	(1,797)
Net income attributable to noncontrolling interests	(301)	(295)
Net loss attributable to IDT Corporation	$ (1,449)	$ (2,092)
Basic and diluted loss per share attributable to IDT Corporation common stockholders	$ (0.06)	$ (0.08)
Weighted-average number of shares used in calculation of basic and diluted loss per share	23,831	24,628
(i) Stock-based compensation included in selling, general and administrative expenses	$ 413	$ 810