Stockholder's Investments - Schedule of Other Activity in Stockholders' Investments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Class of Stock [Line Items]
Other Stockholders Equity	$ (2,159)	$ (720)	$ (3,304)	$ (4,864)
Sale Of Shares At Cost	(141)	(42)	(39)
Purchase Of Shares At Cost	0	0	0
Effect of Deferred Compensation Plan Amendment	(2,435)
Restricted Stock Award, Forfeitures		838
Amortization Of Restricted Stock	1,137	1,788	1,599
Unearned Restricted Stock [Member]
Class of Stock [Line Items]
Other Stockholders Equity	0	(1,137)	(3,763)	(5,362)
Sale Of Shares At Cost	0	0	0
Purchase Of Shares At Cost		0	0
Restricted Stock Award, Forfeitures		838
Amortization Of Restricted Stock	1,137	1,788	1,599
Shares Held Rabbi Trust At Cost [Member]
Class of Stock [Line Items]
Other Stockholders Equity	(9,948)	(10,623)	(11,151)	(11,595)
Ending Balance Other Stockholders Equity Shares	423,415	469,797	517,105	560,078
Sale Of Shares At Cost	1,496	1,419	1,368
Purchase Of Shares At Cost	(821)	(891)	(924)
Restricted Stock Award, Forfeitures		0
Amortization Of Restricted Stock	0	0	0
Deferred Compensation [Member]
Class of Stock [Line Items]
Other Stockholders Equity	7,789	11,040	11,610	12,093
Ending Balance Other Stockholders Equity Shares	338,711	469,797	517,105	560,078
Sale Of Shares At Cost	(1,637)	(1,461)	(1,407)
Purchase Of Shares At Cost	821	891	924
Effect of Deferred Compensation Plan Amendment	(2,435)
Restricted Stock Award, Forfeitures		0
Amortization Of Restricted Stock	$ 0	$ 0	$ 0