Accrued Expenses and Other Current Liabilities (Details) (USD $)	Jan. 31, 2013	Jul. 31, 2012	Jan. 31, 2012	Jul. 31, 2011
Accrued Liabilities, Current [Abstract]
Accrued wages and benefits	$ 9,068,000	$ 16,467,000
Accrued warranty obligations	8,664,000	7,883,000	8,852,000	9,120,000
Accrued commissions and royalties	5,009,000	3,946,000
Accrued business acquisition payments	375,000	1,752,000
Other	7,702,000	10,822,000
Accrued expenses and other current liabilities	$ 30,818,000	$ 40,870,000