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Retirement Benefit Plans - Narrative (Details) - USD ($) $ in Thousands |  | 3 Months Ended
--- | --- | ---
Nov. 26, 2019 | Dec. 31, 2019 | Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items] |  |  |
Contributions amount in defined benefit pension plans |  | $ 188 | $ 22
Additional cash contributions planned during fiscal 2019 |  | 332 |
Other debt withdrawal liability |  | $ 739 |
IAM National Pension Fund [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Payment period | 20 years |  |

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