Restructuring - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 6,840	$ 0
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	883
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	6,492
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	348
Id Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3,977
Workplace Safety [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2,863