Income Taxes - Components of Income/(Loss) Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 24, 2022	Sep. 25, 2021	Sep. 26, 2020
Income Tax Examination [Line Items]
Loss before income tax	$ (139,089)	$ (122,314)	$ (109,568)
U.S.
Income Tax Examination [Line Items]
Loss before income tax	(144,119)	(126,549)	(111,676)
Foreign
Income Tax Examination [Line Items]
Loss before income tax	$ 5,030	$ 4,235	$ 2,108

Amount, before tax, of income (loss) attributable to parent. Includes, but is not limited to, income (loss) from continuing operations, discontinued operations and equity method investments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.20)
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 50
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067

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Balance Type:	credit
Period Type:	duration