Segment Information - Schedule of Segment Reporting Information By Segment (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Segment Reporting Information [Line Items]
Revenues to external customers	$ 297,499	$ 298,421	$ 287,780	$ 290,151	$ 289,212	$ 275,927	$ 268,001	$ 280,176	$ 1,173,851	$ 1,113,316	$ 1,120,625
Depreciation and amortization									25,442	27,303	32,432
Segment profit									175,123	156,126	143,068
Assets	1,056,931				1,050,223				1,056,931	1,050,223	1,043,964
Payments to Acquire Property, Plant, and Equipment									21,777	15,167	17,140
Identification Solutions
Segment Reporting Information [Line Items]
Revenues to external customers									846,087	800,392	795,511
Depreciation and amortization									22,075	23,092	27,285
Segment profit									143,411	130,572	112,276
Assets	737,174				761,448				737,174	761,448	748,408
Payments to Acquire Property, Plant, and Equipment									17,283	12,347	11,640
Workplace Safety
Segment Reporting Information [Line Items]
Revenues to external customers									327,764	312,924	325,114
Depreciation and amortization									3,367	4,211	5,147
Segment profit									31,712	25,554	30,792
Assets	138,329				154,827				138,329	154,827	154,321
Payments to Acquire Property, Plant, and Equipment									4,494	2,820	5,500
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	$ 181,428				$ 133,948				$ 181,428	$ 133,948	$ 141,235