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Retirement Plans (Components Of Net Periodic Benefit Cost) (Details) $ in Thousands |  | 3 Months Ended | 4 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Dec. 31, 2019 | Sep. 29, 2019 USD ($) | Jan. 19, 2020 USD ($) defined_benefit_plan healthcare_plan | Jan. 20, 2019 USD ($) | Sep. 29, 2019
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract] |  |  |  |  |  |
Number of sponsored defined benefit pension plans | defined_benefit_plan |  |  |  | 2 |  |
Lump sum payments from Qualified Plan |  |  | $ 122,300 |  |  |
Number of postretirement health care plans | healthcare_plan |  |  |  | 2 |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Pension settlement |  |  |  | $ (38,600) |  |
Return on asset assumption (percent) |  | 5.90% |  |  |  | 5.80%
Pension Plan |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Interest cost |  |  |  | 5,076 | $ 7,048 |
Expected return on plan assets |  |  |  | (6,656) | (8,104) |
Pension settlement |  |  |  | 38,606 | 0 |
Actuarial loss (gain) | [1] |  |  | 1,672 | 1,219 |
Amortization of unrecognized prior service cost | [1] |  |  | 26 | 35 |
Net periodic benefit cost |  |  |  | 38,724 | 198 |
Postretirement Healthcare Plans |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Interest cost |  |  |  | 248 | 307 |
Actuarial loss (gain) | [1] |  |  | 6 | (49) |
Net periodic benefit cost |  |  |  | $ 254 | $ 258 |
[1] | Amounts were reclassified from accumulated OCI into net earnings as a component of “Other pension and post-retirement expenses, net

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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. + 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 (h)(4) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: 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=118257860&loc=d3e4179-114921 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920 + Details
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- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. + References Reference 1: 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=118257860&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(5) -URI http://asc.fasb.org/extlink&oid=118255775&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 6 -Subparagraph (a)(5) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920 + Details
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