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Investments - Narrative (Detail) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
Apr. 28, 2012
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Jan. 28, 2012
|
Apr. 28, 2012
Minimum [Member]
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Apr. 28, 2012
Maximum [Member]
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Apr. 28, 2012
Auction-rate securities [Member]
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Jan. 28, 2012
Auction Rate Securities and Preferred Stock [Member]
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Apr. 28, 2012
AAA/Aaa-rated [Member]
Auction-rate securities [Member]
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Apr. 28, 2012
AA/Aa-rated [Member]
Auction-rate securities [Member]
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Apr. 28, 2012
A-rated [Member]
Auction-rate securities [Member]
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Apr. 28, 2012
Below A-rated [Member]
Auction-rate securities [Member]
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| Schedule of Investments [Line Items] | ||||||||||
| Securities by credit rating | 16.00% | 57.00% | 16.00% | 11.00% | ||||||
| Available-for-sale securities classified as current | $ 25 | |||||||||
| Available-for-sale securities classified as noncurrent | 14,138 | 14,141 | 14,141 | |||||||
| Long-term investment, held-to-maturity securities | 15,814 | 17,263 | ||||||||
| Accumulated comprehensive income (loss), cumulative unrealized losses on available for sale securities, net of tax | (701) | (699) | ||||||||
| Dutch auction, reset interval | 7 days | 49 days | ||||||||
| Proceeds from sales at par value | $ 25 | |||||||||