Reportable Segment Information (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2015		Jul. 31, 2014		Jul. 31, 2013
Segment Reporting Information [Line Items]
Restructuring Charge	$ (354)	[1],[2]	$ 3,483	[1],[2]	$ 3,519
Intangible assets, net	49,499		57,366
Cash equivalents and marketable securities	86,200		60,900
Pathfinder Therapeutics Inc
Segment Reporting Information [Line Items]
Intangible assets, net	100
Medical Imaging
Segment Reporting Information [Line Items]
Restructuring Charge	(200)		1,700		1,100
Intangible assets, net	23,200		26,000
Ultrasound
Segment Reporting Information [Line Items]
Restructuring Charge	(100)		1,400		2,200
Settlement related charges	1,000
Intangible assets, net	15,200		19,900
Security Technology
Segment Reporting Information [Line Items]
Restructuring Charge	$ (100)		$ 400		$ 200

[1] Activity in fiscal year 2014 pertains to both the Fiscal Year 2014 Restructuring Plan and the 2013 Restructuring Plan. In fiscal year 2014, the restructuring charges of $2.9 million relate to the Fiscal Year 2014 Restructuring Plan, while restructuring charges of $0.6 million and cash payments of ($2.5) million relate to the Fiscal Year 2013 Restructuring Plan.

[2] Activity in fiscal year 2015 pertains to both the Fiscal Year 2014 Restructuring Plan and the 2013 Restructuring Plan. In fiscal year 2015, the restructuring adjustments of ($0.3) million and cash payments of ($2.4) million relate to the Fiscal Year 2014 Restructuring Plan, while restructuring adjustments of ($0.1) million and cash payments of ($0.5) million relate to the Fiscal Year 2013 Restructuring Plan.