Fair Value Measurements - Additional Information (Detail) (Auction rate security, USD $) In Millions, unless otherwise specified	12 Months Ended
Jan. 28, 2012	Jan. 29, 2011
Auction rate security
Fair Value, Measurement Inputs, Disclosure [Line Items]
Preferred stock option security, face value	$ 7	$ 7
Temporary impairment, unrealized loss	$ 2

Fair value of derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

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This item represents the total unrealized gain (loss) included in earnings for the period as a result of holding marketable securities categorized as trading, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period.

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