Derivative Financial Instruments - Fair Value of Interest Rate Contracts Included in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Apr. 27, 2019	Apr. 28, 2018
Derivatives, Fair Value [Line Items]
Interest rate contracts, assets, fair value	$ 380	$ 1,613
Interest rate, liabilities, fair value	3,194	1,613
Interest rate contracts
Derivatives, Fair Value [Line Items]
Interest rate, liabilities, fair value	3,194	1,613
Other non-current assets | Interest rate contracts
Derivatives, Fair Value [Line Items]
Interest rate contracts, assets, fair value	380	1,613
Other accrued liabilities | Interest rate contracts
Derivatives, Fair Value [Line Items]
Interest rate, liabilities, fair value	1,034	0
Other non-current liabilities | Interest rate contracts
Derivatives, Fair Value [Line Items]
Interest rate, liabilities, fair value	$ 2,160	$ 1,613