Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Class A Common Stock	Class B Common Stock
Beginning Balance (in shares) at Jan. 31, 2015						11,546,000	16,544,000
Beginning Balance at Jan. 31, 2015	$ 158,686	$ 28	$ 126,565	$ 32,072	$ 21
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,541			7,541
Shares converted by founders (in shares)						375,000	(375,000)
Stock-based compensation expense	3,926		3,926
Restricted stock (in shares)						48,000
Exercise of stock options (in shares)						336,000
Exercise of stock options	3,094		3,094
Net change in unrealized gain on available-for-sale securities	1				1
Ending Balance (in shares) at Jan. 30, 2016						12,305,000	16,169,000
Ending Balance at Jan. 30, 2016	173,213	28	133,550	39,613	22
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	11,410			11,410
Shares converted by founders (in shares)						840,000	(840,000)
Stock-based compensation expense	2,572		2,572
Restricted stock (in shares)						74,000
Exercise of stock options (in shares)						215,000
Exercise of stock options	2,080	1	2,079
Taxes paid in lieu of shares issued for stock based compensation	(99)		(99)
Net change in unrealized gain on available-for-sale securities	44				44
Ending Balance (in shares) at Jan. 28, 2017						13,434,000	15,329,000
Ending Balance at Jan. 28, 2017	189,220	29	138,102	51,023	66
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment from adoption of ASU 2016-09 | Accounting Standards Update 2016-09			178	(178)
Net income	14,700			14,700
Dividends declared	(29,067)			(29,067)
Dividends paid	(20,080)			(20,080)
Shares converted by founders (in shares)						1,141,000	(1,141,000)
Stock-based compensation expense	$ 2,411		2,411
Restricted stock (in shares)						44,000
Exercise of stock options (in shares)	308,250					308,000
Exercise of stock options	$ 3,394	0	3,394
Taxes paid in lieu of shares issued for stock based compensation	(101)		(101)
Net change in unrealized gain on available-for-sale securities	(52)				(52)
Ending Balance (in shares) at Feb. 03, 2018						14,927,000	14,188,000
Ending Balance at Feb. 03, 2018	$ 160,425	$ 29	$ 143,984	$ 16,398	$ 14