Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Apr. 30, 2016	Jan. 30, 2016	May. 02, 2015
Fair Value, Inputs, Level 1 [Member]
Significant Accounting Policies [Line Items]
Cash equivalents	$ 6,600	$ 22,600	$ 43,900
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	36,159	37,127
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	8	29
Held-to-maturity Securities, Fair Value	36,151	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	1,645	6,916
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	6
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-maturity Securities, Fair Value	1,645	6,923
Municipal Bonds [Member]
Significant Accounting Policies [Line Items]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	55,850	46,335
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	6	6
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	8	29
Held-to-maturity Securities, Fair Value	55,849	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	18,046	2,291
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	6	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-maturity Securities, Fair Value	$ 18,053	$ 2,291