Retirement and Post Retirement Health Care Plans (Schedule Of Fair Value Of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 185.3	$ 160.3
Investments measured at net asset value	60.3	51.5
Common Collective Trust Funds
Defined Benefit Plan Disclosure [Line Items]
Investments measured at net asset value	51.7	45.1
Global Emerging Markets Fund Limited Partnership
Defined Benefit Plan Disclosure [Line Items]
Investments measured at net asset value	8.6	6.4
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	115.4	98.8
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	9.6	10.0	$ 8.1
Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4.4	3.5
Cash and Cash Equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Cash and Cash Equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Common Stock | Level 1 | Domestic Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	27.1	22.9
Common Stock | Level 1 | International Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	14.6	12.6
Common Stock | Level 2 | Domestic Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Common Stock | Level 2 | International Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Common Stock | Level 3 | Domestic Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Common Stock | Level 3 | International Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 1 | U.S. Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25.4	18.8
Mutual Funds | Level 1 | Balanced Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8.3	8.4
Mutual Funds | Level 1 | International Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	19.0	16.2
Mutual Funds | Level 1 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	15.1	15.1
Mutual Funds | Level 1 | Other Plan Asset Category
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1.5	1.3
Mutual Funds | Level 1 | Real Estate Investment
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 2 | U.S. Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 2 | Balanced Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 2 | International Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 2 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 2 | Other Plan Asset Category
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 2 | Real Estate Investment
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 3 | U.S. Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 3 | Balanced Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 3 | International Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 3 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 3 | Other Plan Asset Category
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds | Level 3 | Real Estate Investment
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	9.6	10.0
Estimate of Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	125.0	108.8
Estimate of Fair Value | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4.4	3.5
Estimate of Fair Value | Common Stock | Domestic Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	27.1	22.9
Estimate of Fair Value | Common Stock | International Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	14.6	12.6
Estimate of Fair Value | Mutual Funds | U.S. Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25.4	18.8
Estimate of Fair Value | Mutual Funds | Balanced Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8.3	8.4
Estimate of Fair Value | Mutual Funds | International Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	19.0	16.2
Estimate of Fair Value | Mutual Funds | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	15.1	15.1
Estimate of Fair Value | Mutual Funds | Other Plan Asset Category
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1.5	1.3
Estimate of Fair Value | Mutual Funds | Real Estate Investment
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 9.6	$ 10.0