Reportable Segments Information (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Jan. 31, 2012	Jan. 31, 2012	Jan. 31, 2012 Medical Imaging	Jan. 31, 2012 Medical Imaging	Jan. 31, 2012 Security Technology	Jan. 31, 2012 Security Technology	Jan. 31, 2013 Corporate assets	Jul. 31, 2012 Corporate assets
Segment Reporting Information [Line Items]
Consulting Fees	$ 2,714	$ 2,714	$ 2,198	$ 2,198	$ 516	$ 516
Cash and Cash Equivalents							$ 131,824	$ 153,122