Retirement Plans (Schedule Of Costs Of Retirement Plan) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Pension Cost (Reversal of Cost)	$ 4,733	$ 4,423	$ 4,687
Retirement savings plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Cost (Reversal of Cost)	3,434	3,525	3,343
Deferred compensation plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Cost (Reversal of Cost)	801	508	813
Supplemental executive retirement plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Cost (Reversal of Cost)	$ 498	$ 390	$ 531