Estimated Fair Values of Assets Acquired and Liabilities Assumed (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	Aug. 24, 2011
Business Acquisition [Line Items]
Deferred taxes	$ 2,092

Gross amount of acquisition cost of a business combination allocated to noncurrent deferred tax liabilities.

No definition available.

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