Retirement and Post Retirement Health Care Plans (Schedule Of Defined Benefit Pension Assets Investment) (Details)	12 Months Ended
Dec. 30, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Allocation	100.00%
Target Return	6.90%
Equity investments, Actual Allocation	100.00%	100.00%
Equity Investments
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Allocation	76.00%
Equity investments, Actual Allocation	71.00%	70.00%
Equity Investments \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Return minimum	0.063
Equity Investments \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Return minimum	0.075
Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Allocation	19.00%
Fixed income, Target Return minimum	3.60%
Fixed income, Target Return maximum	4.50%
Equity investments, Actual Allocation	24.00%	25.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Equity investments, Target Allocation	5.00%
Target Return	5.40%
Equity investments, Actual Allocation	5.00%	5.00%

Defined benefit pension assets target return.

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Defined benefit plan target allocation percentage of fixed investment income securities range maximum.

+ References

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Defined benefit plan target allocation percentage of fixed investment income securities range minimum.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

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Description of target allocation percentages, or range of percentages, considering the major categories of plan assets as of the latest statement of financial position presented (on a weighted-average basis for employers with more than one plan) that are pertinent to an understanding of the plan investment policies and strategies.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)(i)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2446-114920

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Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2446-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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