Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Oct. 29, 2016	Jan. 30, 2016	Oct. 31, 2015
Fair Value, Inputs, Level 1 [Member]
Significant Accounting Policies [Line Items]
Cash equivalents	$ 35,800	$ 22,600	$ 4,600
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	6,366	37,127
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	7	29
Held-to-maturity Securities, Fair Value	6,359	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	9,912	46,335
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	6
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	8	29
Held-to-maturity Securities, Fair Value	9,904	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	3,546	2,291
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	1	0
Held-to-maturity Securities, Fair Value	$ 3,545	$ 2,291