Stock-Based Compensation Expense in Selling and Administrative Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jul. 30, 2016	Aug. 01, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 3,075	$ 3,152
Selling and Administrative Expenses | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	210	240
Selling and Administrative Expenses | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	2,561	2,636
Selling and Administrative Expenses | Performance Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 304	67
Selling and Administrative Expenses | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense		$ 209