Equity (Details Textual) (USD $)	1 Months Ended			3 Months Ended
	Nov. 30, 2012	Oct. 31, 2012	Sep. 30, 2012	Oct. 31, 2012	Oct. 31, 2011
Equity (Textual)
Dividends declared, per share				$ 0.75	$ 0.23
Dividend paid per share	$ 0.60	$ 0.15
Aggregate dividends paid	$ 13,700,000	$ 3,400,000		$ 17,125,000
Percentage of equity interest sold by subsidiary			10.00%
Stock based compensation on granted equity of subsidiary				1,200,000
Class B Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Aggregate purchase price of shares repurchased of of Class B common stock				$ 800,000
Stock repurchase program, shares authorized for repurchase of Class B common stock		8,300,000		8,300,000
Stock repurchased of Class B in a fiscal year				77,843	0
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased		5,100,000		5,100,000