Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill	$ 419,815	$ 437,697	$ 429,871
Property, Plant and Equipment, Net	97,945	98,103
Identification Solutions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill	385,524	391,864	384,529
Workplace Safety
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill	$ 34,291	$ 45,833	$ 45,342