Revenue (Effect of Adoption on Financial Statements) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 28, 2018	Oct. 29, 2017	Oct. 28, 2018	Oct. 29, 2017	Jan. 28, 2018
Statements of Income
Net sales	$ 173,550	$ 150,304	$ 467,190	$ 447,233
Cost of sales	66,988	60,885	189,035	180,663
Provision for taxes	(1,454)	3,272	(12,882)	11,124
Net income	$ 12,165	$ 13,338	$ 49,716	$ 37,723
Basic (in dollars per share)	$ 0.18	$ 0.20	$ 0.75	$ 0.57
Diluted (in dollars per share)	$ 0.18	$ 0.20	$ 0.73	$ 0.56
Balance Sheets
Other current assets	$ 18,126		$ 18,126		$ 17,250
Accrued liabilities	60,856		60,856		60,832
Deferred revenue	965		965		$ 12,758
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Statements of Income
Net sales	3,251		9,597
Cost of sales	746		2,190
Provision for taxes	526		1,555
Net income	$ 1,979		$ 5,851
Basic (in dollars per share)	$ 0.03		$ 0.09
Diluted (in dollars per share)	$ 0.03		$ 0.09
Balance Sheets
Deferred revenue	$ (19,889)		$ (19,889)