Segment Reporting (Narrative) (Details)	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
10 Percent Of Net Sales [Member]
Number of customers accounted for net sales	0	0	0
Sales revenue goods net percentage	10.00%	10.00%	10.00%
10 Percent Of Gross Accounts Receivable [Member]
Number of customers accounted for gross accounts receivable	0	0
Gross accounts receivable net percentage	10.00%	10.00%