Intangible Assets (Parenthetical) (Detail) - USD ($) $ in Millions	Apr. 30, 2016	Jul. 31, 2015
Intangible Assets by Major Class [Line Items]
Indefinite-lived Trade names	$ 7.6	$ 7.6
Finite-lived intangible assets	39.8
Trade names
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets	$ 1.0	$ 0.1

Carrying amount (original costs adjusted for previously recognized amortization and impairment) as of the balance sheet date for the rights acquired through registration of a trade name to gain or protect exclusive use thereof for a projected indefinite period of benefit.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

Name:	us-gaap_IndefiniteLivedTradeNames
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant