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Goodwill and Intangible Assets - Narrative (Detail) - USD ($) $ in Thousands |  | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Aug. 28, 2020 | Dec. 25, 2020 | Dec. 27, 2019 | Dec. 25, 2020 | Dec. 27, 2019 | Mar. 27, 2020 | Mar. 29, 2019 | Mar. 29, 2018
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |
Intangible assets amortization expense |  | $ 926 | $ 422 | $ 2,310 | $ 1,267 | $ 1,805 | $ 1,417 |
Goodwill |  | $ 20,249 |  | $ 20,249 |  | $ 1,285 | $ 1,336 | $ 1,467
Patents |  |  |  |  |  |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |
Estimated useful life |  |  |  | 10 years |  | 10 years | 10 years |
Voxtel |  |  |  |  |  |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |
Preliminary purchase price | $ 35,081 |  |  |  |  |  |  |
Goodwill | 18,803 |  |  |  |  |  |  |
Finite-lived intangible assets | 13,600 |  |  |  |  |  |  |
Indefinite-lived intangible assets acquired | $ 2,400 |  |  |  |  |  |  |

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