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Summary of Significant Policies - Concentrations of Credit Risk and Significant Customers (Detail) | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 25, 2020 | Dec. 27, 2019 | Dec. 25, 2020 | Dec. 27, 2019 | Mar. 27, 2020 | Mar. 29, 2019
Customer Concentration Risk | Trade Accounts Receivable, Net | Sanken |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |
Concentration risk, percentage |  |  | 19.80% |  | 33.80% |
Customer Concentration Risk | Total Net Sales | Sanken |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |
Concentration risk, percentage | 16.10% | 10.30% | 17.40% | 10.40% | 28.40% | 26.40%
Customer Concentration Risk | Previously Reported | Trade Accounts Receivable, Net | Sanken |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |
Concentration risk, percentage |  |  |  |  | 33.50% |
Total Net Sales | Geographic Concentration Risk | Non-US |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |
Concentration risk, percentage | 85.40% | 82.80% | 86.10% | 81.80% | 81.70% | 80.50%
Total Net Sales | Geographic Concentration Risk | Japan |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |
Concentration risk, percentage | 16.00% | 28.80% | 17.40% | 27.80% | 28.40% | 26.40%
Total Net Sales | Geographic Concentration Risk | Hong Kong |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |
Concentration risk, percentage |  |  |  |  | 18.70% | 18.30%
Total Net Sales | Geographic Concentration Risk | Greater China |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |
Concentration risk, percentage | 28.10% | 22.10% | 27.90% | 20.00% |  |
Total Net Sales | Geographic Concentration Risk | South Korea |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |
Concentration risk, percentage | 10.70% |  | 10.50% |  |  |

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