Reportable Segment Information (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2016		Jul. 31, 2015		Jul. 31, 2014
Segment Reporting Information [Line Items]
Restructuring Charge	$ 9,641	[1],[2]	$ (354)	[1],[2]	$ 3,483
Intangible assets, net	45,194		49,499
Cash equivalents and marketable securities	97,300		86,200
Pathfinder Therapeutics Inc
Segment Reporting Information [Line Items]
Intangible assets, net	600		100
Medical Imaging
Segment Reporting Information [Line Items]
Restructuring Charge	6,000		(200)		1,700
Intangible assets, net	20,300		23,200
Ultrasound
Segment Reporting Information [Line Items]
Restructuring Charge	1,900		(100)		1,400
Settlement related charges	10,100		1,000
Intangible assets, net	15,200		15,200
Security and Detection
Segment Reporting Information [Line Items]
Restructuring Charge	1,700		$ (100)		$ 400
Oncura
Segment Reporting Information [Line Items]
Intangible assets, net	$ 3,700

[1] 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.

[2] Activity in fiscal year 2016 pertains to the Fiscal Year 2016 Restructuring Plan, the Fiscal Year 2014 Restructuring Plan and the 2013 Restructuring Plan. In fiscal year 2016, there were restructuring charges of $9.6 million and cash payments of ($4.4) million related to the Fiscal Year 2016 Restructuring Plan, while there were cash payments of ($0.2) million and ($0.4) million related to the Fiscal Year 2014 Restructuring Plan and Fiscal Year 2013 Restructuring Plan, respectively.