Reconciliation of Basic and Diluted Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 28, 2017	Oct. 29, 2016	Oct. 28, 2017	Oct. 29, 2016
Numerator for basic loss per share:
Net loss	$ (30,094)	$ (20,409)	$ (40,872)	$ (34,825)
Less allocation of dividends to participating securities	(27)	(188)	(38)	(391)
Net loss available to common shareholders	(30,121)	(20,597)	(40,910)	(35,216)
Numerator for diluted loss per share:
Net loss available to common shareholders	$ (30,121)	$ (20,597)	$ (40,910)	$ (35,216)
Denominator for basic and diluted loss per share:
Basic and diluted weighted average common shares	72,597	72,212	72,525	72,558
Loss per common share:
Basic	$ (0.41)	$ (0.29)	$ (0.56)	$ (0.49)
Diluted	$ (0.41)	$ (0.29)	$ (0.56)	$ (0.49)