Cost Reduction Actions (Activity of Facility Related Exit Costs) (Details) (USD $)	3 Months Ended		6 Months Ended		39 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2012	Jul. 31, 2008
Cost Reduction Actions [Abstract]
Present value of estimated facility-related exit costs, beginning balance			$ 2,518,000		$ 2,100,000	$ 2,100,000
Cash payments made			(499,000)		(3,795,000)
Cash payments received			605,000		3,889,000
Interest accreted on the facility-related exit costs	46,000	40,000	91,000	78,000	521,000
Present value of estimated facility-related exit costs, ending balance	2,715,000		2,715,000		2,715,000	2,100,000
Amount of facility-related exit cost liability recorded as prepaid expenses	406,000		406,000		406,000
Facility-related exit cost liability, Noncurrent	$ 3,121,000		$ 3,121,000		$ 3,121,000