Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Income Statement [Abstract]
Revenues		$ 323,890	$ 349,473	$ 664,089	$ 711,789
Costs and expenses:
Direct cost of revenues (exclusive of depreciation and amortization)		262,716	291,178	542,177	595,870
Selling, general and administrative	[1]	53,789	50,900	107,223	101,452
Depreciation and amortization		5,184	5,762	10,479	11,357
Severance		486		1,112
Total costs and expenses		322,175	347,840	660,991	708,679
Other operating expense, net (see Note 9)		(392)	(2,090)	(3,168)	(3,385)
Income (loss) from operations		1,323	(457)	(70)	(275)
Interest income, net		195	186	467	295
Other income (expense), net		550	496	785	(853)
Income (loss) before income taxes		2,068	225	1,182	(833)
Provision for income taxes		(1,164)	(1,236)	(1,700)	(2,176)
Net income (loss)		904	(1,011)	(518)	(3,009)
Net loss (income) attributable to noncontrolling interests		28	(300)	(63)	(601)
Net income (loss) attributable to IDT Corporation		$ 932	$ (1,311)	$ (581)	$ (3,610)
Earnings (loss) per share attributable to IDT Corporation common stockholders:
Basic		$ 0.04	$ (0.05)	$ (0.02)	$ (0.15)
Diluted		$ 0.04	$ (0.05)	$ (0.02)	$ (0.15)
Weighted-average number of shares used in calculation of earnings (loss) per share:
Basic		26,320	24,816	26,300	24,323
Diluted		26,451	24,816	26,300	24,323
(i) Stock-based compensation included in selling, general and administrative expenses		$ 1,167	$ 467	$ 2,531	$ 880

[1] Stock-based compensation included in selling, general and administrative expenses