Selected Balance Sheet Information - Cash, cash equivalents and restricted cash (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 25, 2022	Sep. 24, 2022	Sep. 25, 2021	Sep. 26, 2020
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 3,514		$ 4,100	$ 5,808
Restricted cash included in other current assets	2,392		0
Restricted cash included in other assets (noncurrent)	8,168		0
Total cash, cash equivalents, and restricted cash shown on the consolidated statements of cash flows	$ 14,074	$ 4,100	$ 4,100	$ 5,808	$ 3,140