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Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details) - USD ($)
$ in Thousands
Jul. 30, 2016
Jan. 30, 2016
Aug. 01, 2015
Fair Value, Inputs, Level 1 [Member]      
Significant Accounting Policies [Line Items]      
Cash equivalents $ 42,400 $ 22,600 $ 40,400
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 6,390 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 6,383 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 28,933 46,335  
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain 4 6  
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss 7 29  
Held-to-maturity Securities, Fair Value 28,930 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 22,543 2,291  
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain 4 0  
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss 0 0  
Held-to-maturity Securities, Fair Value $ 22,547 $ 2,291