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Income Taxes - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2019 | Dec. 30, 2018 | Sep. 29, 2019 | Sep. 30, 2018 | Oct. 01, 2017 | Oct. 02, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |
Effective tax rate (as a percent) |  |  | 9.30% | 21.50% | 31.30% |
Tax Cuts and Jobs Act, transition tax |  |  | $ 2,400 |  |  |
Tax at federal statutory rate |  |  | 21.00% | 24.50% | 35.00% |
Deferred tax benefit from tax reform remeasurement |  | $ 2,600 |  | $ 10,100 |  |
Decrease in deferred tax valuation allowance | $ 23,400 |  |  |  |  |
Effective income tax rate excluding excess tax benefit and TCJA impact |  |  | 21.90% | 25.10% |  |
Tax Cuts And Jobs Act, GILTI Provision |  |  | $ 400 |  |  |
Undistributed earnings of foreign subsidiaries |  |  | 44,000 |  |  |
Incremental federal tax due to repatriation of foreign earnings |  |  | 1,100 |  |  |
Valuation allowance |  |  | 20,543 | $ 21,479 |  |
Unrecognized tax benefits |  |  | 9,169 | 8,328 | $ 9,337 | $ 22,786
Accrued additional interest expense |  |  | 500 | 600 | 400 |
Reduction in accrued interest |  |  | 200 | 300 | 900 |
Amount of interest and penalties accrued |  |  | 2,400 | $ 1,200 | $ 1,100 |
State |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |
Net operating loss carry forwards which expire at various dates |  |  | 43,700 |  |  |
Foreign |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |
Decrease in deferred tax valuation allowance |  |  | 23,400 |  |  |
Net operating loss carry forwards which expire at various dates |  |  | 29,700 |  |  |
Net operating loss carryforwards |  |  | 134,700 |  |  |
Net operating loss carry forwards which have no expiration date |  |  | $ 105,000 |  |  |

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