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Retirement Plans (Fair Values of Qualified Plan's Assets) (Details) - USD ($) $ in Thousands | Oct. 03, 2021 | Sep. 27, 2020
--- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | $ 409,708 | $ 365,510
Cash and cash equivalents |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 1,969 | 3,665
Domestic equities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 66,921 | 83,676
International equities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 63,087 | 81,228
Investment grade |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 219,295 | 126,630
High yield |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 10,156 | 9,270
Alternatives |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 26,519 | 29,375
Real estate |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 21,761 | 31,666
Quoted Prices in Active Markets for Identical (Level 1) |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 128,906 | 136,271
Quoted Prices in Active Markets for Identical (Level 1) | Cash and cash equivalents |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Quoted Prices in Active Markets for Identical (Level 1) | Domestic equities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 66,921 | 83,676
Quoted Prices in Active Markets for Identical (Level 1) | International equities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 31,128 | 40,319
Quoted Prices in Active Markets for Identical (Level 1) | Investment grade |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 20,701 | 3,006
Quoted Prices in Active Markets for Identical (Level 1) | High yield |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 10,156 | 9,270
Quoted Prices in Active Markets for Identical (Level 1) | Alternatives |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Quoted Prices in Active Markets for Identical (Level 1) | Real estate |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Other Observable Inputs (Level 2) |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 200,563 | 127,289
Significant Other Observable Inputs (Level 2) | Cash and cash equivalents |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 1,969 | 3,665
Significant Other Observable Inputs (Level 2) | Domestic equities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Other Observable Inputs (Level 2) | International equities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Other Observable Inputs (Level 2) | Investment grade |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 198,594 | 123,624
Significant Other Observable Inputs (Level 2) | High yield |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Other Observable Inputs (Level 2) | Alternatives |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Other Observable Inputs (Level 2) | Real estate |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Unobservable Inputs (Level 3) |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Unobservable Inputs (Level 3) | Cash and cash equivalents |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Unobservable Inputs (Level 3) | Domestic equities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Unobservable Inputs (Level 3) | International equities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Unobservable Inputs (Level 3) | Investment grade |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Unobservable Inputs (Level 3) | High yield |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Unobservable Inputs (Level 3) | Alternatives |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | 0 | 0
Significant Unobservable Inputs (Level 3) | Real estate |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Fair value of plan assets | $ 0 | $ 0

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