Cash and Cash Equivalents, Short-term Investments and Long-term Investments - Additional Information (Detail) (USD $)	6 Months Ended	12 Months Ended
Jul. 30, 2011	Jul. 31, 2010	Jan. 29, 2011
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sale of available-for-sale securities	$ 115,229,000	$ 27,875,000	$ 177,500,000
Realized loss on sale of investment securities		(225,000)	24,400,000
Purchase of available-for-sale securities	166,443,000	0
Loss on sale of available-for-sale securities previous included in OCI			10,900,000
ARS
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities sold, carrying value			191,400,000
Available-for-sale securities sold, par value			119,700,000
ARS Call Option
Schedule of Available-for-sale Securities [Line Items]
Expiration of right to repurchase securities and/or receive certain additional proceeds			Oct. 29, 2013
Assessed Value Of The ARS Call Option Upon Origination	400,000
Fair value of the ARS Call Option	$ 600,000

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Auction rate securities, at Fair Value

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Expiration date of the option.

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The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

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