Derivative Financial Instruments - Effect of Derivative Instruments in Cash Flow Hedging Relationships on Condensed Consolidated Statements of Income and Other Comprehensive Income (OCI) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jul. 27, 2019	Jul. 28, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated other comprehensive loss expected to be reclassified into earnings	$ (2,900)
Gain (loss) recognized in income on derivative	(3,785)	$ 0
Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated other comprehensive loss expected to be reclassified into earnings	(725)	(733)
Interest rate contract | Other income, net | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in income on derivative	$ (3,785)	$ 0