Cost Reduction Actions (Activity of Facility Related Exit Costs) (Details) (USD $)	3 Months Ended		36 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2011	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	(248,000)		(3,544,000)
Cash payments received	302,000		3,586,000
Interest accreted on the facility-related exit costs	45,000	38,000	475,000
Present value of estimated facility-related exit costs, ending balance	2,617,000		2,617,000	2,100,000
Amount of facility-related exit cost liability recorded as prepaid expenses	402,000		402,000
Facility-related exit cost liability, Noncurrent	$ 3,019,000		$ 3,019,000