Goodwill and Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Jan. 31, 2018 USD ($)
Goodwill [Roll Forward]
Balance as of July 31, 2017	$ 437,697
Goodwill, Translation Adjustments	6,176
Balance as of January 31, 2018	443,873
Id Solutions [Member]
Goodwill [Roll Forward]
Balance as of July 31, 2017	391,864
Goodwill, Translation Adjustments	4,110
Balance as of January 31, 2018	395,974
Workplace Safety [Member]
Goodwill [Roll Forward]
Balance as of July 31, 2017	45,833
Goodwill, Translation Adjustments	2,066
Balance as of January 31, 2018	$ 47,899