Segment Information - Schedule of Segment Reporting Information By Segment (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Segment Reporting Information [Line Items]
Revenues to external customers	$ 289,212	$ 275,927	$ 268,001	$ 280,176	$ 282,106	$ 286,816	$ 268,630	$ 283,073	$ 1,113,316	$ 1,120,625	$ 1,171,731
Depreciation and amortization									27,303	32,432	39,458
Segment profit									156,126	143,068	118,736
Assets	1,050,223				1,043,964				1,050,223	1,043,964	1,062,897
Payments to Acquire Property, Plant, and Equipment									15,167	17,140	26,673
Identification Solutions
Segment Reporting Information [Line Items]
Revenues to external customers									800,392	795,511	826,824
Depreciation and amortization									23,092	27,285	32,228
Segment profit									130,572	112,276	89,392
Assets	761,448				748,408				761,448	748,408	789,924
Payments to Acquire Property, Plant, and Equipment									12,347	11,640	21,483
Workplace Safety
Segment Reporting Information [Line Items]
Revenues to external customers									312,924	325,114	344,907
Depreciation and amortization									4,211	5,147	7,230
Segment profit									25,554	30,792	29,344
Assets	154,827				154,321				154,827	154,321	158,397
Payments to Acquire Property, Plant, and Equipment									2,820	5,500	5,190
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	$ 133,948				$ 141,235				$ 133,948	$ 141,235	$ 114,576