Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Oct. 30, 2021	Jan. 30, 2021	Oct. 31, 2020
Significant Accounting Policies [Line Items]
Amortized Cost	$ 224,563	$ 140,928	$ 96,749
Gross Unrealized Gains	6	0	0
Gross Unrealized Losses	93	60	50
Fair Market Value	224,476	140,868	96,699
Fair Value, Inputs, Level 1
Significant Accounting Policies [Line Items]
Cash equivalents	60,800	250,700	104,700
Corporate bonds | Fair Value, Inputs, Level 2
Significant Accounting Policies [Line Items]
Amortized Cost	190,700	95,530	78,516
Gross Unrealized Gains	6	0	0
Gross Unrealized Losses	82	53	43
Fair Market Value	190,624	95,477	78,473
Municipal bonds | Fair Value, Inputs, Level 2
Significant Accounting Policies [Line Items]
Amortized Cost	33,863	45,398	18,233
Gross Unrealized Gains	0	0	0
Gross Unrealized Losses	11	7	7
Fair Market Value	$ 33,852	$ 45,391	$ 18,226