Consolidated Statements of Equity (USD $) In Thousands	Total	Noncontrolling Interests [Member]	Receivable for Issuance of Equity [Member]	IDT Corp [Member] Additional Paid-In Capital [Member]	IDT Corp [Member] Treasury Stock [Member]	IDT Corp [Member] Accumulated Other Comprehensive Income [Member]	IDT Corp [Member] Accumulated Deficit [Member]	IDT Corp [Member] Common Stock [Member]	IDT Corp [Member] Class A Common Stock [Member]	IDT Corp [Member] Class B Common Stock [Member]
BALANCE at Jul. 31, 2011	$ 203,790	$ (4,305)	$ (1,000)	$ 520,732	$ (94,941)	$ 3,027	$ (219,992)		$ 33	$ 236
BALANCE, SHARES at Jul. 31, 2011									3,272	23,586
Dividends declared	(15,014)						(15,014)
Restricted Class B common stock purchased from employee	(210)				(210)
Repurchases of Class B common stock through repurchase program	(2,606)				(2,606)
Stock-based compensation	3,605			3,605
Restricted stock issued to employees and directors				(4)						4
Restricted stock issued to employees and directors, Shares										433
Stock issued for matching contributions to the 401(k) Plan	911			910						1
Stock issued for matching contributions to the 401(k) Plan, shares	92,843									93
Sale of stock of subsidiary	133	211		(78)
Distributions to noncontrolling interests	(1,580)	(1,580)
Other	225	225
Genie/Straight Path Spin-Off	(123,046)	5,688	1,000	(129,296)		(438)
Other comprehensive income (loss)	(2,268)	119				(2,387)
Net income for the year ended July	38,785	137					38,648
BALANCE at Jul. 31, 2012	102,725	495		395,869	(97,757)	202	(196,358)		33	241
BALANCE, SHARES at Jul. 31, 2012									3,272	24,112
Dividends declared	(18,960)						(18,960)
Restricted Class B common stock purchased from employee	(301)				(301)
Repurchases of Class B common stock through repurchase program	(778)				(778)
Exercise of stock options	921			920						1
Exercise of stock options, Shares										62
Stock-based compensation	6,616	204		6,412
Restricted stock issued to employees and directors				(1)						1
Restricted stock issued to employees and directors, Shares										49
Stock issued for matching contributions to the 401(k) Plan	932			932
Stock issued for matching contributions to the 401(k) Plan, shares	51,861									52
Purchases of stock of subsidiary	1,804	9		1,795
Sale of stock of subsidiary	145	203		(58)
Distributions to noncontrolling interests	(2,245)	(2,245)
Exercise of stock options in subsidiary	9	6		3
Genie/Straight Path Spin-Off	(13,659)	90		(13,749)
Other comprehensive income (loss)	2,091	(48)				2,139
Net income for the year ended July	13,444	1,837					11,607
BALANCE at Jul. 31, 2013	89,136	533		388,533	(98,836)	2,341	(203,711)		33	243
BALANCE, SHARES at Jul. 31, 2013								0	3,272	24,275
Dividends declared	(11,798)						(11,798)
Restricted Class B common stock purchased from employee	(1,005)				(1,005)
Exercise of stock options	609	3		606
Exercise of stock options, Shares										46
Stock-based compensation	5,362	30		5,332
Restricted stock issued to employees and directors				(2)						2
Restricted stock issued to employees and directors, Shares										194
Stock issued for matching contributions to the 401(k) Plan	1,168			1,167						1
Stock issued for matching contributions to the 401(k) Plan, shares	72,281									72
Purchases of stock of subsidiary	(1,133)	21		(1,154)
Distributions to noncontrolling interests	(1,888)	(1,888)
Genie/Straight Path Spin-Off	(1,624)			(1,624)
Other comprehensive income (loss)	1,327					1,327
Net income for the year ended July	21,010	2,226					18,784
BALANCE at Jul. 31, 2014	$ 101,164	$ 925		$ 392,858	$ (99,841)	$ 3,668	$ (196,725)		$ 33	$ 246
BALANCE, SHARES at Jul. 31, 2014									3,272	24,587