Summary of Significant Accounting Policies (Summary Of Estimated Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands	Jul. 31, 2015	Jul. 31, 2014
Carrying value	$ 806,676	$ 625,600
6.50% Notes [Member]
Carrying value	0	215,000
Fair value	0	223,600
Industrial Development Bonds [Member]
Carrying value	0	41,200
Fair value	0	48,003
Other Long-Term Debt [Member]
Carrying value	11,765	5,163
Fair value	$ 12,328	$ 5,758