Segment Information - Schedule of Segment Reporting Information By Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Segment Reporting Information [Line Items]
Revenues from external customers	$ 316,733	$ 309,577	$ 291,194	$ 307,530	$ 310,592	$ 302,483	$ 272,702	$ 272,015	$ 1,225,034	$ 1,157,792	$ 1,071,504
Depreciation and amortization									44,598	48,725	43,987
Total profit from reportable segments									242,367	269,631	277,845
Assets	1,253,665				1,438,683				1,253,665	1,438,683	1,607,719
Payments to Acquire Property, Plant, and Equipment									43,398	35,687	24,147
Identification Solutions [Member]
Segment Reporting Information [Line Items]
Revenues from external customers									825,123	739,116	636,590
Depreciation and amortization									28,955	25,920	18,253
Total profit from reportable segments									176,129	174,390	160,658
Assets	882,440				989,216				882,440	989,216	744,055
Payments to Acquire Property, Plant, and Equipment									28,774	18,186	15,213
Workplace Safety [Member]
Segment Reporting Information [Line Items]
Revenues from external customers									399,911	418,676	434,914
Depreciation and amortization									7,919	9,078	7,827
Total profit from reportable segments									66,238	95,241	117,187
Assets	239,848				239,219				239,848	239,219	439,255
Payments to Acquire Property, Plant, and Equipment									10,580	8,459	4,989
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization									7,724	13,727	17,907
Assets	131,377				210,248				131,377	210,248	424,409
Payments to Acquire Property, Plant, and Equipment									$ 4,044	$ 9,042	$ 3,945