Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jan. 31, 2021		Jan. 31, 2020		Jan. 31, 2021	Jan. 31, 2020
Income Statement [Abstract]
Revenues	$ 339,766		$ 323,890		$ 683,191	$ 664,089
Costs and expenses:
Direct cost of revenues (exclusive of depreciation and amortization)	269,145		262,716		542,319	542,177
Selling, general and administrative	54,298	[1]	53,789	[1]	106,442	107,223
Depreciation and amortization	4,464		5,184		8,956	10,479
Severance	143		486		255	1,112
Total costs and expenses	328,050		322,175		657,972	660,991
Other operating gain (expense), net (see Note 10)	1,207		(392)		955	(3,168)
Income (loss) from operations	12,923		1,323		26,174	(70)
Interest income, net	139		195		98	467
Other income, net	3,170		550		1,792	785
Income before income taxes	16,232		2,068		28,064	1,182
Provision for income taxes	(3,027)		(1,164)		(6,444)	(1,700)
Net income (loss)	13,205		904		21,620	(518)
Net (income) loss attributable to noncontrolling interests	(97)		28		(224)	(63)
Net income (loss) attributable to IDT Corporation	$ 13,108		$ 932		$ 21,396	$ (581)
Earnings (loss) per share attributable to IDT Corporation common stockholders:
Basic (in Dollars per share)	$ 0.52		$ 0.04		$ 0.84	$ (0.02)
Diluted (in Dollars per share)	$ 0.51		$ 0.04		$ 0.83	$ (0.02)
Weighted-average number of shares used in calculation of earnings (loss) per share:
Basic (in Shares)	25,362		26,320		25,448	26,300
Diluted (in Shares)	25,713		26,451		25,787	26,300

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