Segment and Geographic Information - Summary of Property and Equipment, Net by Geographical Region (Detail) - USD ($) $ in Thousands	Mar. 26, 2022	Sep. 25, 2021	Sep. 26, 2020
Long Lived Assets By Geographic Areas [Line Items]
Total property and equipment, net	$ 19,201	$ 18,617	$ 9,186
Percentage of property and equipment, net held outside of the United States	6.00%	7.00%	13.00%
United States [Member]
Long Lived Assets By Geographic Areas [Line Items]
Total property and equipment, net	$ 18,085	$ 17,355	$ 7,978
Canada [Member]
Long Lived Assets By Geographic Areas [Line Items]
Total property and equipment, net	$ 1,116	$ 1,262	$ 1,208

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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