Segment Reporting (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jan. 31, 2012	Jan. 31, 2011
Segment Reporting Information [Line Items]
Number of reportable segments	2
Number of major customers accounted for over 10 percent of gross accounts receivable	1	1
Industrial Products [Member]
Segment Reporting Information [Line Items]
Restructuring expenses		0.7