Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details) $ in Thousands	Jan. 30, 2016 USD ($)
Corporate Bond Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Significant Accounting Policies [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	$ 37,127
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	29
Held-to-maturity Securities, Fair Value	37,098
Certificates of Deposit [Member] \| Fair Value, Inputs, Level 2 [Member]
Significant Accounting Policies [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	6,916
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	6
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0
Held-to-maturity Securities, Fair Value	6,923
Municipal Bonds [Member]
Significant Accounting Policies [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	46,335
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	6
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	29
Held-to-maturity Securities, Fair Value	46,312
Municipal Bonds [Member] \| Fair Value, Inputs, Level 2 [Member]
Significant Accounting Policies [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	2,291
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0
Held-to-maturity Securities, Fair Value	$ 2,291

Significant Accounting Policies [Line Items]

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Amount of accumulated unrealized gain on investments in debt securities classified as held-to-maturity.

+ References

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Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity.

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Amount before other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

+ References

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- Definition

Fair value of investments in debt securities classified as held-to-maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

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