Accumulated appreciation or loss, net of tax, in value of the total of available-for-sale securities at the end of an accounting period.

+ References+ Details

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details

- Definition

Before tax and reclassification adjustments amount of unrealized holding gain (loss) and transfers on available-for-sale securities.

+ References

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-Name Accounting Research Bulletin (ARB)

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+ Details

- Definition

Net of tax amount of unrealized holding gain (loss) before reclassification adjustments and transfers on available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Research Bulletin (ARB)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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+ Details

Short-Term and Long-Term Investments - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Oct. 27, 2012	Oct. 29, 2011	Oct. 27, 2012	Oct. 29, 2011	Jan. 28, 2012
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	$ 10,080,000		$ 10,080,000		$ 16,503,000
Unrealized gains, net of tax	5,000	(28,000)	10,000	40,000
Auction rate securities
Schedule of Available-for-sale Securities [Line Items]
Auction rate securities maturity period			25 years
Auction rate securities interest rate setting interval			28 days
Long-term investments classified as available for sale, fair value of auction rate security	1,700,000		1,700,000		1,700,000
Auction rate securities, cumulative decline from par value, before tax	400,000		400,000
Auction rate securities, cumulative decline from par value, net of tax	200,000		200,000
Unrealized gains, before tax				100,000
Unrealized gains, net of tax				$ 100,000