Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Apr. 30, 2014		Apr. 30, 2013		Apr. 30, 2014		Apr. 30, 2013
Consolidated Statements of Income [Abstract]
Revenues	$ 403,761		$ 396,935		$ 1,230,855		$ 1,208,509
Costs and expenses:
Direct cost of revenues (exclusive of depreciation and amortization)	332,376		331,163		1,017,954		1,010,900
Selling, general and administrative (i)	55,548	[1]	53,997	[1]	170,588	[1]	162,945	[1]
Depreciation and amortization	4,153		3,972		12,108		10,972
Research and development	2,514		1,717		7,387		4,918
Total costs and expenses	394,591		390,849		1,208,037		1,189,735
Other operating gains, net			9,601		1,209		9,251
Income from operations	9,170		15,687		24,027		28,025
Interest expense, net	(135)		(446)		(55)		(798)
Other income (expense), net	159		2,433		(3,455)		5,133
Income from continuing operations before income taxes	9,194		17,674		20,517		32,360
Provision for income taxes	(3,595)		(7,592)		(7,895)		(12,751)
Income from continuing operations	5,599		10,082		12,622		19,609
Loss from discontinued operations, net of tax			(958)				(2,822)
Net income	5,599		9,124		12,622		16,787
Net income attributable to noncontrolling interests	(582)		(433)		(1,548)		(1,529)
Net income attributable to IDT Corporation	5,017		8,691		11,074		15,258
Amounts attributable to IDT Corporation common stockholders:
Income from continuing operations	5,017		9,623		11,074		17,974
Loss from discontinued operations			(932)				(2,716)
Net income attributable to IDT Corporation	5,017		8,691		11,074		15,258
Basic:
Income from continuing operations	$ 0.22		$ 0.46		$ 0.51		$ 0.86
Loss from discontinued operations			$ (0.04)				$ (0.13)
Net income	$ 0.22		$ 0.42		$ 0.51		$ 0.73
Weighted-average number of shares used in calculation of basic earnings per share	22,680		20,905		21,763		20,847
Diluted:
Income from continuing operations	$ 0.22		$ 0.43		$ 0.48		$ 0.81
Loss from discontinued operations			$ (0.04)				$ (0.12)
Net income	$ 0.22		$ 0.39		$ 0.48		$ 0.69
Weighted-average number of shares used in calculation of diluted earnings per share	23,023		22,360		22,893		22,178
Dividends declared per common share	$ 0.17				$ 0.34		$ 0.75
(i) Stock-based compensation included in selling, general and administrative expenses	$ 793		$ 1,523		$ 4,920		$ 4,340

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