Updates to Critical Accounting Policies and Estimates - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Feb. 28, 2015	May 31, 2014
Update Of Summary Of Significant Accounting Policies [Line Items]
Finished Goods Included in inventories	$ 31.1us-gaap_InventoryFinishedGoods	$ 30.9us-gaap_InventoryFinishedGoods
Raw material and Work in progress included in inventories	$ 4.8	$ 3.0

The aggregate carrying amount as of the balance sheet date of items held by the entity which are partially completed at the time of measurement and unprocessed items that will go through the production process and become part of the final product. Includes supplies used directly or indirectly in the manufacturing or production process. This element may be used when the reporting entity combines work in process and raw materials into an aggregate amount.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 6

-Subparagraph a

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a)(3),(4))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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