Activity of Auction Rate Securities, Fair Value Measured using Level 3 Inputs (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 28, 2012	Apr. 28, 2012	Jul. 28, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unrealized gains (losses) included in other comprehensive (loss) income	$ (3)	$ 5	$ 2	[1]

[1] Unrealized gains of $5,000 and unrealized losses $3,000 occurred during the first and second quarters of fiscal 2012, respectively.