Restructuring and Related Charges by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, net
Medical Imaging
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, net	(0.1)
Ultrasound
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, net	0.1
Security Technology
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, net