Fair Values of Financial Instruments - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
Apr. 29, 2017	Apr. 30, 2016	May 02, 2015
Indefinite-lived Intangible Assets [Line Items]
Impairment losses on unamortizable intangible assets	$ 0	$ 3,840	$ 0
Publishing contracts
Indefinite-lived Intangible Assets [Line Items]
Impairment losses on unamortizable intangible assets	$ 3,840	$ 3,840

Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

Name:	us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration