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Income Taxes - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Mar. 31, 2019 | Dec. 30, 2018 | Mar. 29, 2020 | Mar. 31, 2019 | Sep. 29, 2019
Valuation Allowance [Line Items] |  |  |  |  |
Effective tax rate |  |  | 19.50% | (0.80%) |
Tax Cuts and Jobs Act, change in tax rate, income tax benefit |  | $ 2.6 |  |  |
Effective income tax rate reconciliation, tax cuts and jobs act and valuation allowance impacts, percent |  |  |  | 24.80% |
Liability for uncertain tax positions |  |  | $ 9.8 |  | $ 9.2
AUSTRALIA |  |  |  |  |
Valuation Allowance [Line Items] |  |  |  |  |
Valuation allowance release | $ 22.3 |  |  |  |

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