Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended						12 Months Ended
	May 31, 2016	Sep. 30, 2016	Apr. 30, 2016	Jun. 25, 2015	Jan. 30, 2015	Nov. 30, 2014	Aug. 31, 2013	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014	Jan. 22, 2016
Equity (Textual)
Voting rights description								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.
Dividends paid per share in cash					$ 0.64	$ 0.68
Dividends paid								$ 17,400	$ 47,600	$ 13,600
Cash paid to purchase ownership percentage in subsidiary							$ 1,100			1,133
Ownership percentage increased in subsidiary							2.80%
Ownership percentage in subsidiary							88.40%
Cash paid to capital stock								$ 374
Straight Path [Member]
Equity (Textual)
Additional liability										1,900
Additional Paid-in Capital [Member]
Equity (Textual)
Additional liability										$ 1,600
Howard S. Jonas [Member]
Equity (Textual)
Purchase price per share				$ 18.52
Aggregate purchase price of shares repurchased				$ 7,500
Class B common stock shares repurchased				404,967
Class A common stock [Member]
Equity (Textual)
Dividends paid per share in cash								$ 0.75	$ 2.03	$ 0.59
Class A common stock [Member] | Subsequent Event [Member]
Equity (Textual)
Common stock dividends declared		$ 0.19
Paid date of declared dividend		Oct. 20, 2016
Record date of declared dividend		Oct. 11, 2016
Class B common stock [Member]
Equity (Textual)
Dividends paid per share in cash								$ 0.75	$ 2.03	$ 0.59
Aggregate purchase price of shares repurchased								$ 4,600	$ 400
Class B common stock shares repurchased								398,376	29,675
Stock repurchase program, shares authorized for repurchase								8,300,000
Stock repurchase program, remaining number of shares authorized to be repurchased								8,000,000			8,000,000
Stock repurchase program, cancelled number of shares authorized to be repurchased											4,600,000
Class B common stock [Member] | Stock Repurchase Program [Member]
Equity (Textual)
Aggregate purchase price of shares repurchased								$ 100	$ 2,800	$ 1,000
Class B common stock shares repurchased								11,250	152,856	34,206
Class B common stock [Member] | Zedge Spin-Off [Member]
Equity (Textual)
Proceeds from sale of interest in corporate unit total received			$ 3,000
Percentage of capital stock	10.00%
Proceeds from sale of interest in corporate unit intercompany amount paid	$ 2,600
Class B common stock [Member] | Subsequent Event [Member]
Equity (Textual)
Common stock dividends declared		$ 0.19
Paid date of declared dividend		Oct. 20, 2016
Record date of declared dividend		Oct. 11, 2016
Class B common stock [Member] | Other Purchasers [Member] | Zedge Spin-Off [Member]
Equity (Textual)
Cash paid to capital stock	$ 400