Restructuring - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 4,324	$ 1,933	$ 11,163	$ 1,933
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,274		7,765
Asset Write Offs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	97		97
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,335		2,683
Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	618		618
Id Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,458		6,434	1,725
Workplace Safety [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1,866		$ 4,729	$ 208