Restructuring - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 15,012	$ 26,046	$ 6,084
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4,374	3,571	653
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	9,328	18,350	4,947
Asset Write Offs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	267	4,125	458
Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,043		26
Low end of range [Member]
Restructuring Cost and Reserve [Line Items]
Percentage Reduction In Workforce Through Restructuring Programs	5.00%
High end of range [Member]
Restructuring Cost and Reserve [Line Items]
Percentage Reduction In Workforce Through Restructuring Programs	7.00%
Identification Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	9,013	15,870	4,254
Workplace Safety [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 5,999	$ 10,176	$ 1,830