Income Taxes - Contingency (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Valuation Allowance	$ 33,731	$ 28,745
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Interest and Penalties [Roll Forward]
Balance as of the beginning of the year	47,566	20,442	$ 22,538
Increase related to acquisitions	0	25,151	0
Tax positions related to current year:
Additions	19,033	1,326	2,468
Reductions	0	0	0
Tax positions related to prior year:
Additions	117	4,951	424
Reductions	0	(65)	(3,239)
Settlements	0	0	(1,655)
Lapses in statutes of limitations	(700)	(610)	(94)
Decrease in unrecognized tax benefits based on audit results	0	(5,217)	0
Foreign currency revaluation adjustment	(134)
Foreign currency revaluation adjustment		1,588	0
Balance as of end of year	65,882	47,566	$ 20,442
Gross unrecognized tax benefits	70,300
Gross urecognized tax benefits, if recognized, would affect effective tax rate	50,400
Gross interest and penalties accrued	$ 4,400	$ 2,800

Unrecognized Tax Benefits, Current Period Tax Positions [Abstract]

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The amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date, including interest and penalties

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Unrecognized Tax Benefits, Prior Period Tax Positions [Abstract]

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Unrecognized tax benefit changes resulting from settlements

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of unrecognized tax benefits.

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Amount of decrease in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of increase in unrecognized tax benefits resulting from foreign currency translation.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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