Income Taxes - Reconciliation of unrecognized tax benefits (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Jan. 01, 2017	Sep. 29, 2019	Sep. 30, 2018
Reconciliation of unrecognized tax benefits [Roll Forward]
Beginning balance	$ 22,786	$ 8,328	$ 9,337
Additions for current year tax positions	1,060	1,342	1,928
Additions for prior year tax positions	2,365	356	1,116
Reductions for prior year tax positions	(6,875)	(100)	0
Settlements	$ (9,999)	(757)	(4,053)
Ending balance		$ 9,169	$ 8,328

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

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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- Definition

Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

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- Definition

Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

+ References

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- Definition

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

+ References

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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