Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Oct. 31, 2020	Feb. 01, 2020	Nov. 02, 2019
Significant Accounting Policies [Line Items]
Amortized Cost	$ 96,749	$ 59,229	$ 54,072
Gross Unrealized Gains	0	0	48
Gross Unrealized Losses	50	4	0
Fair Market Value	96,699	59,225	54,120
Fair Value, Inputs, Level 1
Significant Accounting Policies [Line Items]
Cash equivalents	104,700	200,100	64,300
Corporate bonds \| Fair Value, Inputs, Level 2
Significant Accounting Policies [Line Items]
Amortized Cost	78,516	58,625	53,996
Gross Unrealized Gains	0	0	48
Gross Unrealized Losses	43	4	0
Fair Market Value	78,473	58,621	54,044
Municipal bonds \| Fair Value, Inputs, Level 2
Significant Accounting Policies [Line Items]
Amortized Cost	18,233	604	76
Gross Unrealized Gains	0	0	0
Gross Unrealized Losses	7	0	0
Fair Market Value	$ 18,226	$ 604	$ 76

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Significant Accounting Policies [Line Items]

+ References

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- Definition

Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27232-111563

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27232-111563

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Amount, before other-than-temporary impairment (OTTI) accretion, of investment in debt securities measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
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