Fair Value Measurements (Schedule of Assets Measure at Fair Value on Recurring Basis) (Details) - USD ($) $ in Thousands	Aug. 03, 2019	Feb. 02, 2019	Aug. 04, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents - money market mutual funds	$ 15,684	$ 68,500	$ 31,124
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents - money market mutual funds	15,684	68,500	31,124
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents - money market mutual funds	0	0	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents - money market mutual funds	$ 0	$ 0	$ 0