Net Earnings (Loss) Per Share - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				9 Months Ended
	Jan. 27, 2018	Jul. 29, 2017	Jan. 28, 2017	Jul. 30, 2016	Jan. 27, 2018	Jan. 28, 2017	Dec. 14, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock Repurchase Program, Authorized Amount							$ 50,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 26,669				$ 26,669
Shares Paid for Tax Withholding for Share Based Compensation					259
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,844		339		2,477	395
Net Income (Loss) Attributable to Parent	$ (283,235)		$ 3,761		$ (269,623)	$ 5,134
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	0		(1)		0	(3)
Net Income (Loss) Available to Common Stockholders, Basic	(283,235)		3,760		(269,623)	5,131
Undistributed Earnings, Basic	0		1		0	3
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted	0		1		0	(3)
Net Income (Loss) Attributable to Parent, Diluted	$ (283,235)		$ 3,760		$ (269,623)	$ 5,131
Weighted Average Number of Shares Outstanding, Basic	46,914,000		46,276,000		46,712,000	46,265,000
Average dilutive restricted stock units	0		512,000		0	397,000
Average dilutive performance shares	0		52,000		0	33,000
Average dilutive restricted shares	0		4,000		0	21,000
Average dilutive performance share units	0		0		0	0
Average Dilutive Options	0		0		0	0
Weighted Average Number of Shares Outstanding, Diluted	46,914,000		46,844,000		46,712,000	46,716,000
Earnings Per Share, Basic	$ (6.04)		$ 0.08		$ (5.77)	$ 0.11
Earnings Per Share, Diluted	$ (6.04)		$ 0.08		$ (5.77)	$ 0.11