Description of Business and Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Apr. 24, 2020	Jul. 27, 2019	Apr. 26, 2019
Description Of Business And Significant Accounting Policies [Line Items]
Operating lease ROU assets, net of deferred rent and lease restructuring liabilities	$ 137		$ 0
Operating lease liabilities	$ 144
Minimum
Description Of Business And Significant Accounting Policies [Line Items]
Capitalized commissions amortization period	1 year
Minimum | Developed Technology
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years
Minimum | Customer Contracts/Relationships
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years
Minimum | Covenants not to Compete
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years
Minimum | Trademarks and Trade Names
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years
Maximum
Description Of Business And Significant Accounting Policies [Line Items]
Capitalized commissions amortization period	3 years
Maximum | Developed Technology
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Maximum | Customer Contracts/Relationships
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Maximum | Covenants not to Compete
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years
Maximum | Trademarks and Trade Names
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
ASC 842
Description Of Business And Significant Accounting Policies [Line Items]
Operating lease ROU assets, net of deferred rent and lease restructuring liabilities		$ 149
Operating lease liabilities		158
Cumulative-effect adjustment to retained earnings		$ (6)	$ 6