Earnings per share - Reconciliations of Basic and Diluted Share Calculations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Jan. 31, 2015		Nov. 01, 2014		Aug. 02, 2014		May 03, 2014		Feb. 01, 2014		Nov. 02, 2013		Aug. 03, 2013		May 04, 2013		Jan. 31, 2015	Feb. 01, 2014	Feb. 02, 2013
Earnings Per Share Disclosure [Line Items]
Net income	$ 262		$ 29,856		$ 32,679		$ 5,183	[1]	$ 4,680		$ 41,189		$ 35,649		$ 20,912		$ 67,980	$ 102,430	$ 102,585
Weighted Average Number of Shares Outstanding, Diluted
Weighted average shares outstanding																	45,172	45,490	47,494
Weighted average shares outstanding assuming dilution																	45,608	45,955	48,094
Basic Earnings per Share
Basic earnings per share	$ 0.01	[2]	$ 0.65	[2]	$ 0.70	[2]	$ 0.11	[2]	$ 0.10	[2]	$ 0.90	[2]	$ 0.76	[2]	$ 0.45	[2]	$ 1.47	$ 2.21	$ 2.13
Diluted Earnings per Share
Diluted earnings per share	$ 0.01	[2]	$ 0.65	[2]	$ 0.70	[2]	$ 0.11	[2]	$ 0.10	[2]	$ 0.89	[2]	$ 0.76	[2]	$ 0.44	[2]	$ 1.46	$ 2.19	$ 2.10
Earnings Per Share, Basic. [Member]
Earnings Per Share Disclosure [Line Items]
Net income																	67,980	102,430	102,585
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic																	1,376	1,983	1,470
Net Income Available to Common Stockholders, Basic																	66,604	100,447	101,115
Weighted Average Number of Shares Outstanding, Diluted
Weighted average shares outstanding																	45,172	45,490	47,494
Basic Earnings per Share
Basic earnings per share																	$ 1.47	$ 2.21	$ 2.13
Earnings Per Share, Diluted. [Member]
Earnings Per Share Disclosure [Line Items]
Net income																	67,980	102,430	102,585
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted																	1,363	1,963	1,452
Net Income Available to Common Stockholders, Diluted																	$ 66,617	$ 100,467	$ 101,133
Weighted Average Number of Shares Outstanding, Diluted
Effect of dilutive securities																	436	465	600
Weighted average shares outstanding assuming dilution																	45,608	45,955	48,094
Diluted Earnings per Share
Diluted earnings per share																	$ 1.46	$ 2.19	$ 2.10

[1] Net income for the first quarter of Fiscal 2014 reflects the $10.2 million after-tax impact of a $17.3 million pre-tax restructuring charge.

[2] The sum of the quarterly per share data may not equal the annual amounts due to quarterly changes in the weighted average shares and share equivalents outstanding.