Changes in Carrying Amount of Goodwill (Parenthetical) (Detail) $ in Thousands	Apr. 27, 2013 USD ($)
Goodwill [Line Items]
Tax basis of goodwill in excess of related basis	$ 96,576

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration