Retirement and Post Retirement Health Care Plans (Schedule Of Defined Benefit Pension Assets Investment) (Details)	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Allocation	100.00%
Target Return	7.00%
Equity investments, Actual Allocation	100.00%	100.00%
Equity Investments
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Allocation	73.00%
Fixed income, Target Return minimum	6.60%
Fixed income, Target Return maximum	8.00%
Equity investments, Actual Allocation	70.00%	67.50%
Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Allocation	22.00%
Fixed income, Target Return minimum	2.70%
Fixed income, Target Return maximum	5.50%
Equity investments, Actual Allocation	25.00%	27.40%
Other
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Allocation	5.00%
Target Return	5.20%
Equity investments, Actual Allocation	5.00%	5.10%