Revenue (Effect of Adoption on Financial Statements) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 29, 2018	Jul. 30, 2017	Jul. 29, 2018	Jul. 30, 2017	Jan. 28, 2018
Statements of Income
Net sales	$ 163,211	$ 153,127	$ 293,640	$ 296,929
Cost of sales	63,087	60,891	122,047	119,778
Provision for taxes	6,082	4,095	(11,428)	7,852
Net income	$ 25,169	$ 12,564	$ 37,551	$ 24,385
Basic (in dollars per share)	$ 0.38	$ 0.19	$ 0.57	$ 0.37
Diluted (in dollars per share)	$ 0.37	$ 0.19	$ 0.55	$ 0.36
Balance Sheets
Other current assets	$ 20,346		$ 20,346		$ 17,250
Accrued liabilities	55,791		55,791		60,832
Deferred revenue	$ 5,100		$ 5,100		$ 12,758