Product Warranty Costs - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Nov. 30, 2011
Warranty Liability [Line Items]
Purchase accounting adjustment	$ (5,719)

Represents the aggregate Increase or Decrease in the liability during the reporting period for accruals related to preexisting standard and extended product warranties (including adjustments for changes in estimates).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 8

-Subparagraph ((c)(4))

-URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249

Name:	us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration