Description of Business and Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jul. 27, 2018	Apr. 26, 2019
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		6 years
Maximum | Customer Contracts/Relationships
Description Of Business And Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life		8 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		7 years
ASU 2016-16
Description Of Business And Significant Accounting Policies [Line Items]
Cumulative-effect adjustment to decrease retained earnings	$ (51)