Income Taxes - Summary of Effective Income Tax Expense Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017
Income Tax Disclosure [Abstract]
Tax at U.S. statutory rate	$ 22,306	$ 54,674	$ 87,807
State tax provision, net of federal benefit	3,492	4,650	5,217
Effect of foreign taxes	2,728	(186)	(2,602)
ESOP	(2,465)	(4,036)	(4,198)
Other permanent differences	1,074	(728)	(2,663)
Tax on dividends, net of foreign tax credit	0	0	(2,406)
Tax reform	(2,686)	(76,648)	0
Other	(1,097)	563	(4,062)
Income tax expense (benefit)	$ 23,352	$ (21,711)	$ 77,093