Derivative Financial Instruments - Fair Value of Derivative Instruments Included in Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Jul. 25, 2020	Apr. 25, 2020
Derivatives, Fair Value [Line Items]
Interest rate contracts, assets, fair value	$ 160	$ 204
Interest rate contracts, liabilities, fair value	18,173	19,849
Other Noncurrent Assets | Interest rate contracts
Derivatives, Fair Value [Line Items]
Interest rate contracts, assets, fair value	160	204
Other Accrued Liabilities | Interest rate contracts
Derivatives, Fair Value [Line Items]
Interest rate contracts, liabilities, fair value	5,977	6,789
Other Noncurrent Liabilities | Interest rate contracts
Derivatives, Fair Value [Line Items]
Interest rate contracts, liabilities, fair value	$ 12,196	$ 13,060