Immaterial Corrections to Prior Period Financial Statements - Consolidated Statements of Stockholders' Equity (Deficit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 25, 2022	Sep. 26, 2021	Sep. 27, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 41,097	$ (44,992)
Net income (loss)	97	24,792	$ (130)
Ending Balance	15,005	41,097	(44,992)
As previously reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	54,565	(31,564)
Net income (loss)		24,832	(1,261)
Ending Balance		54,565	(31,564)
Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(13,468)	(13,428)
Net income (loss)		(40)	1,131
Ending Balance		(13,468)	(13,428)
Accumulated deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(259,212)	(281,957)	(279,982)
Net income (loss)	97	24,792	(130)
Ending Balance	(261,229)	(259,212)	(281,957)
Accumulated deficit | As previously reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(245,744)	(268,529)	(265,423)
Net income (loss)		24,832	(1,261)
Ending Balance		(245,744)	(268,529)
Accumulated deficit | Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ (13,468)	(13,428)	(14,559)
Net income (loss)		(40)	1,131
Ending Balance		$ (13,468)	$ (13,428)