Note 4 - Fair Value Measurements - Financial Assets and Liabilities (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Apr. 30, 2021	Jan. 30, 2021	Jan. 31, 2020
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Cash and cash equivalents	$ 117,109		$ 80,611
Fair Value, Inputs, Level 1 [Member] | Certificates of Deposit [Member]
Cash and cash equivalents	11,838		9,262
Fair Value, Inputs, Level 2 [Member]
Liability related to the interest rate swap	(261)	$ (325)	(325)
Fair Value, Inputs, Level 3 [Member]
Contingent liability associated with acquisitions	$ (5,417)		$ (4,751)