CONSOLIDATED STATEMENTS OF STOCKHOLDERS' INVESTMENT - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Increase Decrease In Stockholders Equity Roll Forward
Common Stock, Value, Issued	$ 548	$ 548	$ 548
Beginning Balances	587,688
Net earnings (loss)	80,110	2,987	(45,968)
Other comprehensive (loss) income, net of tax	(9,711)	(109,190)	8,093
Stock-based compensation expense	8,154	4,471	5,214
Purchase of shares of Class A Common Stock	(23,552)	0	(30,581)
Ending Balances	603,598	587,688
Additional Paid-in Capital [Member]
Increase Decrease In Stockholders Equity Roll Forward
Beginning Balances	314,403	311,811	306,191
Issuance of shares of Class A Common Stock under stock plan	(3,830)	(1,315)	847
Stockholder's equity, other	(10)	2,312	(371)
Tax (shortfall) benefit from exercise of stock options, vesting of RSUs, and deferred compensation distributions	(1,716)	(2,876)	(70)
Stock-based compensation expense	8,154	4,471	5,214
Ending Balances	317,001	314,403	311,811
Retained Earnings [Member]
Increase Decrease In Stockholders Equity Roll Forward
Beginning Balances	414,069	452,057	538,512
Net earnings (loss)	80,110	2,987	(45,968)
Payment of Ordinary Dividends, Common Stock Class A	(38,001)	(38,204)	(37,786)
Payment of Ordinary Dividends, Common Stock Class B	(2,807)	(2,771)	(2,701)
Ending Balances	453,371	414,069	452,057
Treasury Stock [Member]
Increase Decrease In Stockholders Equity Roll Forward
Beginning Balances	(93,234)	(93,337)	(69,797)
Issuance of shares of Class A Common Stock under stock plan	8,300	2,735	11,266
Stockholder's equity, other	(228)	(2,632)	(4,225)
Purchase of shares of Class A Common Stock	(23,552)		(30,581)
Ending Balances	(108,714)	(93,234)	(93,337)
Accumulated Other Comprehensive Income (Loss) [Member]
Increase Decrease In Stockholders Equity Roll Forward
Beginning Balances	(45,034)	64,156	56,063
Other comprehensive (loss) income, net of tax	(9,711)	(109,190)	8,093
Ending Balances	(54,745)	(45,034)	64,156
Other equity component [Member]
Increase Decrease In Stockholders Equity Roll Forward
Beginning Balances	(3,064)	(2,159)	(720)
Stockholder's equity, other	(799)	(905)	(1,439)
Ending Balances	$ (3,863)	$ (3,064)	$ (2,159)