Acquisitions (Details) (USD $)	1 Months Ended	12 Months Ended			48 Months Ended
	Oct. 31, 2010	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2014
Business Acquisition [Line Items]
Benefit related to a change in fair value of contingent earn-out liability		$ 239,000	$ 3,267,000	$ 918,000
Payment of contingent consideration		49,000	97,000	195,000
Acquisition of Stampede Technologies, Inc. [Member]
Business Acquisition [Line Items]
Name of Acquired Entity		Stampede Technologies, Inc.
Effective date of acquisition	Oct. 01, 2010
Aggregate purchase price	5,303,000
Initial fair value of contingent consideration	3,803,000
Interest accreted on the contingent earn-out liability					986,000
Benefit related to a change in fair value of contingent earn-out liability		239,000	3,267,000	918,000
Final cash purchase price					1,865,000
Payment of contingent consideration					$ 365,000