Restructuring - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended					12 Months Ended
	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Jul. 31, 2012	Apr. 30, 2012	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 15,573	$ 8,540	$ 1,933	$ 4,107	$ 1,977	$ 26,046	$ 6,084	$ 6,451
Other Restructuring Cost [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						3,571	679	536
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges							653	293
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						18,350	4,947	4,338
Asset Write Offs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						4,125	458	1,577
Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges							26	243
Low end of range [Member]
Restructuring Cost and Reserve [Line Items]
Percentage Reduction In Workforce Through Restructuring Programs						0.00%
Restructuring charges						13,000
High end of range [Member]
Restructuring Cost and Reserve [Line Items]
Percentage Reduction In Workforce Through Restructuring Programs						0.00%
Restructuring charges						16,000
Identification Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						15,870	4,254	2,896
Workplace Safety [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						$ 10,176	$ 1,830	$ 3,555