Debt - Derivatives (Details) - USD ($) $ in Millions	Dec. 27, 2020	Apr. 28, 2019
Interest rate swap, April 2018, 2.33% fixed
Interest rate swaps
Interest rate swap agreement, notional amount	$ 55.0
Interest rate swap agreement, fixed interest rate	2.33%
Interest rate swap, April 2018, 2.36% fixed
Interest rate swaps
Interest rate swap agreement, notional amount	$ 35.0
Interest rate swap agreement, fixed interest rate	2.36%
Interest rate swap, April 2018, 2.34% fixed
Interest rate swaps
Interest rate swap agreement, notional amount	$ 35.0
Interest rate swap agreement, fixed interest rate	2.34%
Interest rate swap, January 2018, 1.99% fixed, $100 million notional amount
Interest rate swaps
Interest rate swap agreement, notional amount	$ 100.0
Interest rate swap agreement, fixed interest rate	1.99%
Interest rate swap, January 2018, 1.99% fixed, $75 million notional amount
Interest rate swaps
Interest rate swap agreement, notional amount	$ 75.0
Interest rate swap agreement, fixed interest rate	1.99%
Interest rate swap, January 2018, 2.00% fixed, $50 million notional amount
Interest rate swaps
Interest rate swap agreement, notional amount	$ 50.0
Interest rate swap agreement, fixed interest rate	2.00%
Interest rate swap
Interest rate swaps
Interest rate swap agreement, notional amount	$ 350.0
Terminated interest rate swaps
Interest rate swaps
Interest rate swap agreement, notional amount		$ 50.0