Goodwill Impairment (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014
Goodwill Impairment
Goodwill, Impaired, Accumulated Impairment Loss	$ 190,505
Id Solutions [Member]
Goodwill Impairment
Goodwill, Impaired, Accumulated Impairment Loss	18,225
Workplace Safety [Member]
Goodwill Impairment
Goodwill, Impaired, Accumulated Impairment Loss	$ 172,280

Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a,h)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

Name:	us-gaap_GoodwillImpairedAccumulatedImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant