Investments (Amortized Cost and Fair Value of Available-for-sale Securities) (Details) (USD $) In Thousands	Apr. 30, 2011	Jan. 29, 2011	May 01, 2010
Amortized cost	$ 14,720	$ 16,535	$ 17,494
Unrealized gains	779	793	689
Unrealized losses	(33)	(42)	(385)
Fair value	15,466	17,286	17,798
Short-term	3,275	3,204	1,941
Long-term	12,191	14,082	15,857
Auction-Rate Securities [Member]
Amortized cost			1,050
Unrealized gains
Unrealized losses			(150)
Fair value			900
Short-term
Long-term			900
Corporate Securities [Member]
Amortized cost	7,170	7,465	9,352
Unrealized gains	608	634	583
Unrealized losses	(33)	(37)	(54)
Fair value	7,745	8,062	9,881
Short-term		300	1,016
Long-term	7,745	7,762	8,865
U.S. Government and Agency Securities [Member]
Amortized cost	6,589	7,959	5,243
Unrealized gains	80	77	31
Unrealized losses		(5)	(178)
Fair value	6,669	8,031	5,096
Short-term	2,809	2,366	353
Long-term	3,860	5,665	4,743
Mortgage-Backed Securities [Member]
Amortized cost	961	1,111	1,849
Unrealized gains	91	82	75
Unrealized losses			(3)
Fair value	1,052	1,193	1,921
Short-term	466	538	572
Long-term	$ 586	$ 655	$ 1,349

This item represents the total of all debt securities grouped by maturity dates, at cost, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments, as defined), and fair value hedge accounting adjustments, if any, which are classified neither as held-to-maturity nor trading securities.

+ References+ Details

For an unclassified balance sheet, total of debt securities categorized neither as held-to-maturity nor trading.

+ References

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

- Definition

Total of debt securities categorized neither as held-to-maturity nor trading which are intended be sold or mature within one year from the balance sheet date or the normal operating cycle, whichever is longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

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-Publisher FASB
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-Number 133
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 43
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-Section A
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-Paragraph 1
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+ Details

- Definition

Total of debt securities categorized neither as held-to-maturity nor trading which are intended be sold or mature more than one year from the balance sheet date or operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 12
-Subparagraph b
-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.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Number FAS115-1/124-1
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
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Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6379932&loc=d3e22054-111558

+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details