Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Oct. 27, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	$ 56,661
Deferred compensation plan (long-term)	4,933
Money market funds (cash equivalent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	44,851
Municipal Bonds | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	10,080
Auction rate securities | Long-term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	1,730
Quoted Prices in Active Markets for Identical Items (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	44,851
Quoted Prices in Active Markets for Identical Items (Level 1) | Money market funds (cash equivalent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	44,851
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	10,080
Deferred compensation plan (long-term)	4,933
Significant Other Observable Inputs (Level 2) | Municipal Bonds | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	10,080
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	1,730
Significant Unobservable Inputs (Level 3) | Auction rate securities | Long-term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	$ 1,730