Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 28, 2024	Sep. 30, 2023	Sep. 24, 2022	Sep. 25, 2021
Deferred tax assets:
Net operating losses	$ 49,735	$ 21,703
Investment in Symbotic Holdings, LLC	600,917	439,547
Tax Receivable Agreement	32,065	24,574
Other	264	409
Credits	9,269	7,184
Total deferred tax assets before valuation allowance	692,250	493,417
Valuation allowance	(690,231)	(486,920)	$ (168,308)	$ (12,608)
Total deferred tax assets after valuation allowance	2,019	6,497
Deferred tax liabilities:
Foregone FTC	(178)	(575)
ROU asset	(125)	(286)
Foreign R&D credit recapture	(722)	(718)
Total deferred tax liabilities	(1,025)	(1,579)
Net deferred tax asset	$ 994	$ 4,918