Supplemental Financial Information - Other Non-Current Assets (Detail) - USD ($) $ in Millions	Jan. 25, 2019	Apr. 27, 2018
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Deferred tax assets	$ 219	$ 229
Other assets	277	221
Other non-current assets	$ 496	$ 450

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards classified as noncurrent.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant