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Income Taxes (Narrative) (Details) - USD ($) $ in Thousands |  | 12 Months Ended |
--- | --- | --- | ---
Dec. 22, 2018 | Sep. 27, 2019 | Sep. 28, 2018 | Sep. 29, 2017 | Sep. 30, 2016
Income Tax Contingency [Line Items] |  |  |  |  |
Valuation Allowance |  | $ 153,257 | $ 256,948 |  |
Measurement period adjustments on effective tax rate |  | 1 year |  |  |
Income tax expense | $ 144,400 |  |  |  |
Income tax expense resulting from the differential of the losses netted again uncertain tax positions |  | $ 24,400 |  |  |
Additions based on tax positions related to the current year |  | 7,455 | 9,780 | $ 5,900 |
One time estimated tax on post 1986 earnings |  | 800 |  |  |
Estimated valuation allowance |  |  | $ (256,900) |  |
Valuation allowance, deferred tax asset, increase (decrease), amount |  | $ 103,700 |  |  |
Statutory tax rate |  | 21.00% | 24.60% | 35.00% |
Benefit from foreign valuation allowance release |  | $ (29,125) | $ (5,088) | $ (3,085) |
Foreign tax credits |  | (15,682) | (21,735) | (16,337) |
Foreign deferred adjustments |  | 17,900 |  |  |
Uncertain tax positions |  | (6,883) | (1,402) | (5,624) |
Change in enacted tax rate, amount |  | 119,100 | 139,800 |  |
Change in deferred tax assets valuation allowance, amount |  | (207) | 104,221 | 0 |
Federal hurricane credit |  | 36,600 | 5,700 |  |
IRS §179D deduction |  | $ 2,957 | $ 4,557 | $ 2,613 |
Effective income tax rate (percent) |  | 10.50% | 98.40% | 30.10% |
Repatriation of foreign earnings, income tax expense |  | $ 29,800 |  |  |
Nonrecurring benefit |  |  | $ 2,800 |  |
Gross unrecognized tax benefits |  | 104,355 | 179,140 | $ 38,580 | $ 44,167
Accrued interest and penalties |  | 51,100 | 56,300 |  |
Decrease in unrecognized tax benefits |  | 4,300 |  |  |
Foreign income Tax rate to new US Statutory rate of prior year differential, amount |  |  | 19,800 |  |
Foreign Country |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Loss carry forwards of foreign subsidiaries |  | 710,500 | 470,400 |  |
United States Federal Tax Authority |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Loss carry forwards of foreign subsidiaries |  | 234,600 |  |  |
Expiring Between 2018 and 2037 | Foreign Country |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Loss carry forwards of foreign subsidiaries |  | 84,600 |  |  |
No Expiration Date | Foreign Country |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Loss carry forwards of foreign subsidiaries |  | 6,100 |  |  |
Accounting Standards Update 2013-11 |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Gross unrecognized tax benefits |  | 85,200 | $ 76,700 |  |
Retained Earnings |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Cumulative effect of change on retained earnings |  | (37,209) |  |  |
Retained Earnings | Accounting Standards Update 2018-02 |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Cumulative effect of change on retained earnings |  | 10,200 |  |  |
Write off of Deferred Tax Asset |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Valuation allowance, deferred tax asset, increase (decrease), amount |  | 85,400 |  |  |
Deferred Tax Assets Acquired |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Valuation allowance, deferred tax asset, increase (decrease), amount |  | $ (10,900) |  |  |

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