Net Income Per Share - Reconciliations of Basic and Diluted Share Calculations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 27, 2012	Oct. 29, 2011	Oct. 27, 2012	Oct. 29, 2011
Earnings Per Share Disclosure [Line Items]
Net income	$ 40,748	$ 32,280	$ 100,215	$ 84,386
Weighted Average Number of Shares Outstanding, Diluted
Weighted average shares outstanding	47,422	51,389	47,638	51,583
Effect of dilutive securities (shares)	551	683	618	858
Weighted average shares outstanding assuming dilution	47,973	52,072	48,256	52,441
Basic Earnings per Share
Basic earnings per share (dollars per share)	$ 0.85	$ 0.62	$ 2.07	$ 1.61
Diluted Earnings per Share
Diluted earnings per share (dollars per share)	$ 0.84	$ 0.61	$ 2.05	$ 1.58
Earnings Per Share, Basic
Earnings Per Share Disclosure [Line Items]
Net income	40,748	32,280	100,215	84,386
Undistributed Earnings Allocated to Participating Securities	562	544	1,454	1,425
Net Income Available to Common Stockholders, Basic	40,186	31,736	98,761	82,961
Earnings Per Share, Diluted
Earnings Per Share Disclosure [Line Items]
Net income	40,748	32,280	100,215	84,386
Undistributed Earnings Allocated to Participating Securities	555	537	1,436	1,402
Net Income Available to Common Stockholders, Diluted	$ 40,193	$ 31,743	$ 98,779	$ 82,984