Revenue - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
Jan. 25, 2019	Apr. 27, 2018
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 308	$ 289
Revenue recognized that was previously included in deferred revenue	170
Estimated revenue expected to be recognized in future periods related to unsatisfied performance obligations	$ 700
Period over which remaining performance obligations are expected to be recognized as revenue	3 years
Other accrued expenses
Disaggregation of Revenue [Line Items]
Rebate obligations	$ 715	614
Deferred revenue	209	196
Reduction of accounts receivable
Disaggregation of Revenue [Line Items]
Rebate obligations	426	376
Other liabilities
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 99	$ 93

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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