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Retirement Plans (Narrative) (Details) |  | 4 Months Ended | 8 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jan. 01, 2016 | Jan. 19, 2020 USD ($) | Sep. 27, 2020 USD ($) | Sep. 27, 2020 USD ($) defined_benefit_plan | Sep. 29, 2019 USD ($) | Sep. 30, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Number of sponsored defined benefit pension plans | defined_benefit_plan |  |  |  | 2 |  |
Lump sum payments from qualified plan |  | $ 122,300,000 |  |  |  |
Pension settlement |  | $ 38,600,000 | $ 600,000 |  |  |
Minimum required contribution for retirement plans |  |  | $ 0 | $ 0 |  |
Qualified Pension Plan |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Lump sum payments from qualified plan |  |  |  | $ 124,253,000 | $ 3,808,000 |
Qualified Defined Contribution Plan |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Minimum age of eligible employees |  |  |  | 21 years |  |
Employer matching contribution, percent of match | 100.00% |  |  |  |  |
Employer matching contribution, percent of employees' gross pay | 4.00% |  |  |  |  |
Defined contribution plan, Company contributions |  |  |  | $ 1,600,000 | 1,700,000 | $ 2,200,000
Non-Qualified Deferred Compensation Plan |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Employer matching contribution, percent of employees' gross pay |  |  |  | 4.00% |  |
Defined contribution plan, Company contributions |  |  |  | $ 300,000 | $ 200,000 | $ 200,000
Maximum annual contributions per employee, percent |  |  |  | 50.00% |  |
Maximum annual contributions per employee, percent of bonus |  |  |  | 85.00% |  |
Period of years in executive position |  |  |  | 10 |  |

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- Definition Defined contribution plan, minimum age of eligible employees. + References No definition available. + Details
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- Definition Number Of Defined Benefit Pension Plans Sponsored + References No definition available. + Details
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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk related to obligation and assets used to effect settlement. + 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)(7) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(7) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920 + Details
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