Equity (Details Textual) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
May 31, 2016	Jul. 31, 2017
Equity (Textual)
Common stock, voting rights		The holders of Class A common stock are entitled to three votes per share and the holders of Class B common stock are entitled to one-tenth of a vote per share. Each share of Class A common stock may be converted into one share of Class B common stock, at any time, at the option of the holder.
Class B common stock [Member]
Equity (Textual)
Capital stock	$ 3
Percentage of capital stock	10.00%

The holders of Class A common stock are entitled to three votes per share and the holders of Class B common stock are entitled to one-tenth of a vote per share. Each share of Class A common stock may be converted into one share of Class B common stock, at any time, at the option of the holder.

10.00%