Shareholders' Equity (Details) $ in Thousands	1 Months Ended		3 Months Ended
	Aug. 31, 2016 USD ($)	Aug. 31, 2015 USD ($)	Oct. 29, 2016 USD ($) shares	Oct. 31, 2015 USD ($) shares	Jul. 31, 2016 USD ($)	Aug. 31, 2010 shares
Cash Dividends [Abstract]
Cash dividends declared | $			$ 0	$ 0
Dividends paid | $	$ 900	$ 1,000
Accumulated Other Comprehensive Loss [Abstract]
Unrealized net foreign currency translation losses | $			(2,168)		$ (2,176)
Unrealized net investment gains on available for sale investments | $			22		33
Total accumulated other comprehensive loss | $			$ (2,146)		$ (2,143)
Class A [Member]
Class A and Class B common stock [Abstract]
Percentage equity holders entitled to elect Board of Directors			25.00%
Minimum percentage of the number of outstanding Class A shares to combined classes of shares			10.00%
Voting power of Class A common share holders to the Class B common share holders			0.1
Number of Class B shares to be converted into Class A shares (in shares) | shares			1
Stock Repurchase [Abstract]
Number of shares authorized to be repurchased (in shares) | shares						200,000
Number of shares repurchased during the period (in shares) | shares			122,918
Remaining number of shares authorized to be repurchased (in shares) | shares			77,082
Number of share acquired (in shares) | shares			0	0