Stock Option Activity Under Stock Option Plan (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Jul. 28, 2012
Stock option
Beginning Balance	1,540,000
Granted year-to-date	670,500
Exercised year-to-date	(30,250)
Forfeited year-to-date	(11,250)
Ending Balance	2,169,000
Exercisable ending balance	975,625
Grant date weighted average exercise price
Beginning Balance	$ 11.34
Granted year-to-date	$ 15.53
Exercised year-to-date	$ 8.67
Forfeited year-to-date	$ 14.52
Ending Balance	$ 12.66
Exercisable ending balance	$ 9.62
Outstanding at July 28, 2012	7 years 9 months 18 days
Exercisable at July 28, 2012	6 years
Outstanding at July 28, 2012	$ 7,713	[1]
Exercisable at July 28, 2012	$ 6,416	[1]

[1] Intrinsic value for stock options is defined as the difference between the market price of the Company's Class A common stock on the last business day of the fiscal quarter and the weighted average exercise price of in-the-money stock options outstanding at the end of each fiscal period. The market value per share was $16.19 at July 27, 2012.