Significant Accounting Policies - Insurance Reserves and Derivatives (Details) - USD ($)	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017	Apr. 28, 2019
Derivative Financial Instruments
Other comprehensive income (loss), before tax	$ (10,783,000)	$ 4,254,000	$ 1,421,000
Other comprehensive income (loss), net of tax	(8,300,000)	$ 3,200,000	$ 900,000
Minimum
Insurance Reserves
Employee insurance retention limit per occurrence	100,000
Maximum
Insurance Reserves
Employee insurance retention limit per occurrence	$ 1,000,000.0
Terminated interest rate swaps
Derivative Financial Instruments
Interest rate swap agreement, notional amount				$ 50,000,000.0