Stockholder's Investments - Schedule of Other Activity in Stockholders' Investments (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Class of Stock [Line Items]
Sale Of Shares At Cost	$ (90)	$ (141)	$ (42)
Purchase Of Shares At Cost	(815)	0	0
Forfeitures of Restricted Stock			838
Amortization Of Restricted Stock		1,137	1,788
Effect of Deferred Compensation Plan Amendment		(2,435)
Ending Balance, Other Stockholders Equity	(3,064)	(2,159)	(720)	$ (3,304)
Unearned Restricted Stock [Member]
Class of Stock [Line Items]
Sale Of Shares At Cost	0	0	0
Purchase Of Shares At Cost	0	0	0
Forfeitures of Restricted Stock			838
Amortization Of Restricted Stock		1,137	1,788
Effect of Deferred Compensation Plan Amendment		0
Ending Balance, Other Stockholders Equity	0	0	(1,137)	(3,763)
Shares Held Rabbi Trust At Cost [Member]
Class of Stock [Line Items]
Sale Of Shares At Cost	2,235	1,496	1,419
Purchase Of Shares At Cost	(1,035)	(821)	(891)
Forfeitures of Restricted Stock			0
Amortization Of Restricted Stock		0	0
Effect of Deferred Compensation Plan Amendment		0
Ending Balance, Other Stockholders Equity	$ (8,748)	$ (9,948)	$ (10,623)	$ (11,151)
Ending Balance, Other Stockholders Equity Shares	362,025	423	470	517
Deferred Compensation [Member]
Class of Stock [Line Items]
Sale Of Shares At Cost	$ (2,325)	$ (1,637)	$ (1,461)
Purchase Of Shares At Cost	220	821	891
Forfeitures of Restricted Stock			0
Amortization Of Restricted Stock		0	0
Effect of Deferred Compensation Plan Amendment		(2,435)
Ending Balance, Other Stockholders Equity	$ 5,684	$ 7,789	$ 11,040	$ 11,610
Ending Balance, Other Stockholders Equity Shares	252,261	339	470	517