Stock-Based Compensation Expense in Selling and Administrative Expenses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended			6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Nov. 01, 2014	Oct. 26, 2013	Nov. 01, 2014	Oct. 26, 2013	Jul. 27, 2013 Restricted Stock Units (RSUs)	Nov. 01, 2014 Selling and administrative expenses Restricted Stock	Oct. 26, 2013 Selling and administrative expenses Restricted Stock	Nov. 01, 2014 Selling and administrative expenses Restricted Stock	Oct. 26, 2013 Selling and administrative expenses Restricted Stock	Nov. 01, 2014 Selling and administrative expenses Restricted Stock Units (RSUs)	Oct. 26, 2013 Selling and administrative expenses Restricted Stock Units (RSUs)	Nov. 01, 2014 Selling and administrative expenses Restricted Stock Units (RSUs)	Oct. 26, 2013 Selling and administrative expenses Restricted Stock Units (RSUs)	Nov. 01, 2014 Selling and administrative expenses Stock Options	Oct. 26, 2013 Selling and administrative expenses Stock Options	Nov. 01, 2014 Selling and administrative expenses Stock Options	Oct. 26, 2013 Selling and administrative expenses Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 8,665	$ 1,459	$ 13,271	$ 5,681	$ 1,883	$ 283	$ 584	$ 551	$ 1,293	$ 6,575	$ 1,042	$ 10,604	$ 5,994	$ 1,807	$ (167)	$ 2,116	$ (1,606)