Revenue - Summary of Components of Deferred Revenue and Financed Unearned Services Revenue (Detail) - USD ($) $ in Millions	Oct. 25, 2019	Apr. 26, 2019	Oct. 26, 2018	Apr. 27, 2018
Contract With Customer Liability [Line Items]
Deferred revenue and financed unearned services revenue	$ 3,468	$ 3,668	$ 3,206	$ 3,363
Short-term	1,718	1,825
Long-term	1,750	1,843
Deferred product revenue
Contract With Customer Liability [Line Items]
Deferred revenue and financed unearned services revenue	85	84
Deferred services revenue
Contract With Customer Liability [Line Items]
Deferred revenue and financed unearned services revenue	3,314	3,502
Financed unearned services revenue
Contract With Customer Liability [Line Items]
Deferred revenue and financed unearned services revenue	$ 69	$ 82