Property and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 17,123	$ 15,450
Less accumulated depreciation	7,884	6,889
Property and equipment, net	9,239	8,561
Depreciation expense	1,093	972	986
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	730	730
Building and improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,896	5,965
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,974	6,992
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,222	730
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,014	363
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 287	$ 670