Equity (Details) (USD $)	6 Months Ended		1 Months Ended	3 Months Ended		0 Months Ended		1 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Aug. 31, 2014	Jan. 31, 2015	Jan. 31, 2014	Jan. 05, 2015	Jan. 16, 2015	Sep. 30, 2014	Jan. 15, 2015
Equity (Textual)
Common stock issued for exercises of stock options	$ (26,000)
Number of shares held in treasury stock, shares	31,741			31,741
Number of shares held in treasury stock, value	283,048			283,048
Treasury stock, shares	32,000			32,000
Proceeds from sale of treasury stock	65,000
Class B common stock [Member]
Equity (Textual)
Number of shares held in treasury stock, shares								35,846
Number of shares held in treasury stock, value								348,051
Additional shares issued for amendment of stock option and incentive plan	350,000
Stock-based compensation expense	1,229,223	497,682		845,961	341,388
Number of restricted shares issued, value			1,214,000
Description of restricted shares vesting condition			One-third of both grants of restricted shares vested on March 16, 2015 and the remaining vest as to approximately one-third of the granted shares on each of February 1, 2016 and 2017.
Class B common stock [Member] | Director [Member]
Equity (Textual)
Stock issued during period, Shares	207,000
Common stock issued for exercises of stock options, Shares	4,625,000
Common stock issued for exercises of stock options	26,223,000
Number of restricted shares issued, shares						24,000
Number of restricted shares issued, value						438,000
Class B common stock [Member] | Davidi Jonas [Member]
Equity (Textual)
Number of restricted shares issued, shares			71,000
Class B common stock [Member] | Officer [Member]
Equity (Textual)
Treasury stock, shares									4,105,000
Proceeds from sale of treasury stock							65,003
Class B common stock [Member] | Jonathan Rand [Member]
Equity (Textual)
Number of restricted shares issued, shares			52,000
Class B common stock [Member] | Zhouyue (Jerry) Pi [Member]
Equity (Textual)
Number of restricted shares issued, shares								60,000
Number of restricted shares issued, value								$ 573,000
Description of restricted shares vesting condition								These restricted shares vest as to one-third of the granted shares on each of September 1, 2015, 2016 and 2017.
Class B common stock [Member] | IDT [Member]
Equity (Textual)
Number of restricted shares issued to former employees	1,000