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Benefit Plans - Pension Assets by Percentage (Details) - Pension Plan [Member] | 12 Months Ended
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Dec. 30, 2017 | Dec. 31, 2016
Asset category [Abstract] |  |
Total plan assets | 100.00% | 100.00%
Expected long-term rate of return on plan assets | 5.27% | 5.56%
Equity Securities [Member] |  |
Asset category [Abstract] |  |
Total plan assets | 46.00% | 47.00%
Fixed Income Funds [Member] |  |
Asset category [Abstract] |  |
Total plan assets | 48.00% | 48.00%
Cash and Cash Equivalents [Member] |  |
Asset category [Abstract] |  |
Total plan assets | 3.00% | 3.00%
Alternative Investments [Member] |  |
Asset category [Abstract] |  |
Total plan assets | 3.00% | 2.00%
Minimum [Member] | Fixed Income Funds [Member] |  |
Asset category [Abstract] |  |
Total plan assets | 60.00% |
Maximum [Member] | Equity Securities [Member] |  |
Asset category [Abstract] |  |
Total plan assets | 30.00% |
Maximum [Member] | Alternative Investments [Member] |  |
Asset category [Abstract] |  |
Total plan assets | 5.00% |

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- Definition Refers to the expected long term return on plan assets. + References No definition available. + Details
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- Definition 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=65897934&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=65897934&loc=d3e1928-114920 + Details
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