Noncontrolling Interests - Schedule of Common Stock Outstanding (Details) - shares		12 Months Ended
	Jun. 07, 2022	Sep. 28, 2024	Sep. 30, 2023
Common Stock, Shares, Outstanding [Roll Forward]
Beginning of period (in shares)		556,572,919	553,889,249
Issuances (in shares)		29,391,040	3,051,364
Exchanges (in shares)		0	0
Cancellation of Class V-1 common stock (in shares)		0	(367,694)
End of period (in shares)	528,441,744	585,963,959	556,572,919
Symbotic, Inc.
Common Stock, Shares, Outstanding [Roll Forward]
Ownership percentage		100.00%	100.00%
Class A Common Stock
Common Stock, Shares, Outstanding [Roll Forward]
Beginning of period (in shares)		82,112,881	57,718,836
Issuances (in shares)		13,520,629	3,051,364
Exchanges (in shares)		9,055,867	21,342,681
Cancellation of Class V-1 common stock (in shares)		0	0
End of period (in shares)		104,689,377	82,112,881
Class A Common Stock | Symbotic, Inc.
Common Stock, Shares, Outstanding [Roll Forward]
Ownership percentage		17.90%	14.80%
Common Voting Shares, Class V-1 and V-3
Common Stock, Shares, Outstanding [Roll Forward]
Beginning of period (in shares)		474,460,038	496,170,413
Issuances (in shares)		15,870,411	0
Exchanges (in shares)		(9,055,867)	(21,342,681)
Cancellation of Class V-1 common stock (in shares)		0	(367,694)
End of period (in shares)		481,274,582	474,460,038
Common Voting Shares, Class V-1 and V-3 | Symbotic, Inc.
Common Stock, Shares, Outstanding [Roll Forward]
Ownership percentage		82.10%	85.20%