Derivatives and Hedging Activities - Schedule of Notional Value of Outstanding Foreign Currency Forward Contracts (Detail) - Foreign Exchange Forward Contracts - USD ($) $ in Millions	Oct. 26, 2018	Apr. 27, 2018
Long | Cash Flow Hedges
Derivative [Line Items]
Forward contracts, Notional Amount	$ 182	$ 0
Non Designated | Long | Balance Sheet Contracts
Derivative [Line Items]
Forward contracts, Notional Amount	237	412
Non Designated | Short | Balance Sheet Contracts
Derivative [Line Items]
Forward contracts, Notional Amount	$ 101	$ 115