Stockholders' Equity (Schedule Of Stock Award Activity) (Details) (USD $)	12 Months Ended
	Jul. 31, 2010	Jul. 31, 2009
Stockholders' Equity
Nonvested, Beginning of year, Shares	4,000	32,000
Vested, Shares	(4,000)	(28,000)
Nonvested, End of year, Shares		4,000
Nonvested, Beginning of year, Weighted Average Grant Date Fair Value	$ 26.91	$ 19.22
Vested, Weighted Average Grant Date Fair Value	$ 26.91	$ 18.12
Nonvested, End of year, Weighted Average Grant Date Fair Value		$ 26.91