Income (Loss) Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
Apr. 28, 2018	Apr. 29, 2017	Apr. 30, 2016
Schedule Of Components Of Income Loss Before Income Taxes [Line Items]
Domestic operations	$ (137,693)	$ 47,127	$ 6,827
Foreign operations	(2)	(328)	(941)
Income (loss) before income taxes	$ (137,695)	$ 46,799	$ 5,886

Components Of Income Loss Before Income Taxes [Line Items]

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- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

+ References

+ Details

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- Definition

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

+ References

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