Income Taxes (Schedule Of Reconciliation Of U.S. Statutory Income Tax Rate With Effective Income Tax Rate) (Details)	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Income Tax Disclosure [Abstract]
Statutory U.S. federal rate	35.00%	35.00%	35.00%
State income taxes	0.90%	0.80%	0.90%
Foreign operations	(8.30%)	(8.10%)	(7.90%)
Export, manufacturing and research credits	(1.10%)	(1.60%)	(1.10%)
Change in unrecognized tax benefits	1.00%	(1.00%)	1.30%
Other	0.20%	0.80%	(0.30%)
Effective income tax rate	27.70%	25.90%	27.90%