Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 26, 2022	Sep. 25, 2021	Mar. 27, 2021	Sep. 26, 2020
Level 3
Liabilities:
Liability for contingent consideration	$ 1,481	$ 1,606	$ 1,180	$ 1,369
Recurring
Liabilities:
Liability for contingent consideration	1,481	1,606	1,180
Total liabilities	1,481	1,606	1,180
Recurring | Level 1
Liabilities:
Liability for contingent consideration	0	0	0
Total liabilities	0	0	0
Recurring | Level 2
Liabilities:
Liability for contingent consideration	0	0	0
Total liabilities	0	0	0
Recurring | Level 3
Liabilities:
Liability for contingent consideration	1,481	1,606	1,180
Total liabilities	$ 1,481	$ 1,606	$ 1,180