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Benefit Plans - Pension Assets by Percentage (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 29, 2018 | Dec. 30, 2017 | Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Long-term asset | $ 164,603 | $ 186,336 |
Cash and Cash Equivalents [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Long-term asset | 12,984 | 5,364 |
Pension Plan [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Long-term asset | $ 164,603 | $ 186,336 | $ 169,140
Asset category [Abstract] |  |  |
Total plan assets | 100.00% | 100.00% |
Expected long-term rate of return on plan assets | 5.05% | 5.27% |
Pension Plan [Member] | Equity Securities [Member] |  |  |
Asset category [Abstract] |  |  |
Total plan assets | 35.00% | 46.00% |
Pension Plan [Member] | Fixed Income Funds [Member] |  |  |
Asset category [Abstract] |  |  |
Total plan assets | 54.00% | 48.00% |
Pension Plan [Member] | Cash and Cash Equivalents [Member] |  |  |
Asset category [Abstract] |  |  |
Total plan assets | 8.00% | 3.00% |
Pension Plan [Member] | Alternative Investments [Member] |  |  |
Asset category [Abstract] |  |  |
Total plan assets | 3.00% | 3.00% |
Pension Plan [Member] | Minimum [Member] | Fixed Income Funds [Member] |  |  |
Asset category [Abstract] |  |  |
Total plan assets | 60.00% |  |
Pension Plan [Member] | Maximum [Member] | Equity Securities [Member] |  |  |
Asset category [Abstract] |  |  |
Total plan assets | 30.00% |  |
Pension Plan [Member] | Maximum [Member] | Alternative Investments [Member] |  |  |
Asset category [Abstract] |  |  |
Total plan assets | 5.00% |  |

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- Definition Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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- Definition Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(i) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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