Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Aug. 01, 2020	Feb. 01, 2020	Aug. 03, 2019
Significant Accounting Policies [Line Items]
Amortized Cost	$ 41,670	$ 59,229	$ 90,325
Gross Unrealized Gains	65	0	8
Gross Unrealized Losses	0	4	0
Fair Market Value	41,735	59,225	90,333
Fair Value, Inputs, Level 1
Significant Accounting Policies [Line Items]
Cash equivalents	144,100	200,100	167,900
Corporate bonds | Fair Value, Inputs, Level 2
Significant Accounting Policies [Line Items]
Amortized Cost	41,670	58,625	89,018
Gross Unrealized Gains	65	0	7
Gross Unrealized Losses	0	4	0
Fair Market Value	$ 41,735	58,621	89,025
Municipal bonds | Fair Value, Inputs, Level 2
Significant Accounting Policies [Line Items]
Amortized Cost		604	1,307
Gross Unrealized Gains		0	1
Gross Unrealized Losses		0	0
Fair Market Value		$ 604	1,308
Corporate bonds | Fair Value, Inputs, Level 2
Significant Accounting Policies [Line Items]
Amortized Cost			1,043
Gross Unrealized Gains			0
Gross Unrealized Losses			0
Fair Market Value			1,043
Other Long-term Investments
Significant Accounting Policies [Line Items]
Amortized Cost			1,043
Gross Unrealized Gains			0
Gross Unrealized Losses			0
Fair Market Value			$ 1,043