Stock-Based Compensation (Details) (USD $)	0 Months Ended	12 Months Ended			0 Months Ended	1 Months Ended	12 Months Ended		1 Months Ended		1 Months Ended	12 Months Ended
	Apr. 15, 2013	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013 IDT[Member]	Apr. 15, 2013 Straight Path IP [Member]	May 31, 2013 Straight Path IP [Member]	Jul. 31, 2013 Straight Path IP [Member]	Jul. 31, 2012 Straight Path IP [Member]	Sep. 24, 2012 Straight Path IP [Member] Howard Jonas [Member]	Jul. 31, 2013 Straight Path IP [Member] Employee [Member]	May 31, 2011 Straight Path IP [Member] Former CEO [Member]	Jul. 31, 2013 Straight Path IP [Member] May 31, 2014 [Member]	Jul. 31, 2013 Common Class B [Member]	Jul. 31, 2013 Common Class B [Member] Jonathan Rand [Member]	Jul. 31, 2013 Common Class B [Member] Davidi Jonas [Member]	Jul. 31, 2013 Common Class B [Member] Non Employee Director [Member]	Jul. 31, 2013 Common Class B [Member] IDT[Member]
Stock-Based Compensation (Textual)
Common stock shares reserved													678,532
Common stock options purchase				641,567									32,155
Common stock shares outstanding option, percentage				10.00%
Exercise option price per share													$ 5.67
Number of share granted to non-employee directors														38,268	229,608	3,750
Common stock with aggregate fair value									$ 700,000				$ 1,500,000			$ 21,263
Common stock restricted shares																	1,000,000
Restricted common stock shares description		Both grants of restricted shares will vest as to one-third of the granted shares on each of August 2, 2014, 2015 and 2016.
Estimated value of grant option Srtaight Path IP										13,318	200,000
Description of spin off restricted shares				One share of the Company's Class B common stock for every two restricted shares of IDT
Stock option purchase of consultant, percentage	0.50%										5.00%
Consultant stock option vests percentage					33.20%	33.40%						33.40%
Board of Directors approved a grant of equity percentage									10.00%
Grant options equity outstanding of Srtaight Path IP											400,000
Expected volatility											49.00%	51.00%
Discount rate											2.20%	0.80%
Expected term											6 years	4 years
Stock-based compensation		$ 675,000	$ 52,000				$ 13,000	$ 52,000