Restructuring - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2014	Oct. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 4,278	$ 6,840
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,588	6,492
Asset Write Offs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	200
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	948	348
Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	542
Id Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,386	3,977
Workplace Safety [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1,892	$ 2,863