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v3.21.1

Nature of the Business and Basis of Presentation - Additional Information (Details) |  |  |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | ---
Feb. 02, 2021 USD ($) shares | Nov. 02, 2020 USD ($) $ / shares shares | Oct. 14, 2020 USD ($) | Mar. 28, 2020 USD ($) | Oct. 31, 2017 | Mar. 27, 2020 USD ($) | Mar. 26, 2021 USD ($) location continent | Mar. 27, 2020 USD ($)
Noncash or Part Noncash Divestitures [Line Items] |  |  |  |  |  |  |  |
Percentage of ownership interest sold |  |  |  |  | 0.288 |  |  |
Number of locations | location |  |  |  |  |  |  | 16 |
Number of continents on which entity operates | continent |  |  |  |  |  |  | 4 |
Estimated offering costs |  |  |  |  |  |  | $ 1,790,000 |
Noncash or part noncash divestiture, amount of consideration received |  |  |  |  |  |  | 0 | $ 0
Equity investment in related party |  |  |  |  |  | $ 0 | 26,664,000 | $ 0
Adjustments to additional paid in capital, capitalization changes |  |  |  |  |  |  | 19,165,000 |
IPO |  |  |  |  |  |  |  |
Noncash or Part Noncash Divestitures [Line Items] |  |  |  |  |  |  |  |
Number of shares issued in transaction (in shares) | shares | 0 | 28,750,000 |  |  |  |  |  |
Offering price (in dollars per share) | $ / shares |  | $ 14.00 |  |  |  |  |  |
Net proceeds | $ 0 | $ 321,425,000 |  |  |  |  |  |
Underwriting discounts |  | 20,125,000 |  |  |  |  |  |
Estimated offering costs |  | $ 8,450,000 |  |  |  |  |  |
IPO - Selling Shareholders |  |  |  |  |  |  |  |
Noncash or Part Noncash Divestitures [Line Items] |  |  |  |  |  |  |  |
Number of shares issued in transaction (in shares) | shares | 19,332,852 | 3,750,000 |  |  |  |  |  |
COVID-19 |  |  |  |  |  |  |  |
Noncash or Part Noncash Divestitures [Line Items] |  |  |  |  |  |  |  |
Proceeds from unsecured credit facilities |  |  |  |  |  | $ 43,000,000 |  |
Estimated cash benefit, CARES Act, net operating losses |  |  |  |  |  |  | 9,069,000 |
Estimated cash benefit, CARES Act, qualified improvement property |  |  |  |  |  |  | 1,680,000 |
Estimated deferred payroll taxes, CARES Act |  |  |  |  |  |  | 2,766,000 |
Estimated deferred payroll taxes, CARES Act to be paid, third quarter of fiscal year 2022 |  |  |  |  |  |  | 1,383,000 |
Allegro Microsystems, Inc. | IPO |  |  |  |  |  |  |  |
Noncash or Part Noncash Divestitures [Line Items] |  |  |  |  |  |  |  |
Number of shares issued in transaction (in shares) | shares |  | 25,000,000 |  |  |  |  |  |
Disposal Group, Disposed of by Sale, Not Discontinued Operations | PSL |  |  |  |  |  |  |  |
Noncash or Part Noncash Divestitures [Line Items] |  |  |  |  |  |  |  |
Noncash or part noncash divestiture, amount of consideration received |  |  |  | $ 42,700,000 |  |  |  |
Noncash or part noncash divestiture, amount of consideration transferred |  |  |  | $ 15,000,000 |  |  |  |
Equity method investment, ownership percentage |  |  |  | 30.00% |  |  |  |
Equity investment in related party |  |  |  | $ 25,250,000 |  |  |  |
Income from equity method investments |  |  |  |  |  |  | 1,413,000 |
Adjustments to additional paid in capital, capitalization changes |  |  |  |  |  |  | 19,165,000 |
Adjustments to additional paid in capital, income tax benefit from noncash or part noncash divestiture |  |  |  |  |  |  | 1,552,000 |
Disposal Group, Disposed of by Sale, Not Discontinued Operations | PSL | Sanken |  |  |  |  |  |  |  |
Noncash or Part Noncash Divestitures [Line Items] |  |  |  |  |  |  |  |
Ownership percentage by majority shareholder |  |  |  | 70.00% |  |  |  |
Disposal Group, Disposed of by Sale, Not Discontinued Operations | PSL | PSL |  |  |  |  |  |  |  |
Noncash or Part Noncash Divestitures [Line Items] |  |  |  |  |  |  |  |
Related party debt |  |  |  | $ 66,377,000 |  |  |  |
Note receivable from related party |  |  |  | $ 51,377,000 |  |  |  |
Repayments of related party notes receivable |  |  | $ 51,377,000 |  |  |  |  |
Interest payable |  |  | 762,000 |  |  |  | $ 762,000 |
Interest paid |  |  | $ 762,000 |  |  |  |  |

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