Accrued Expenses and Other Current Liabilities (Details) (USD $)	Oct. 31, 2012	Jul. 31, 2012	Oct. 31, 2011	Jul. 31, 2011
Accrued Liabilities, Current [Abstract]
Accrued wages and benefits	$ 9,966,000	$ 16,467,000
Accrued warranty obligations	8,510,000	7,883,000	9,283,000	9,120,000
Accrued commissions and royalties	5,209,000	3,946,000
Accrued business acquisition payments	1,248,000	1,752,000
Other	8,155,000	10,822,000
Accrued expenses and other current liabilities	$ 33,088,000	$ 40,870,000