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Retirement Plans - Narrative (Details) £ in Thousands, $ in Thousands | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Dec. 25, 2020 USD ($) | Dec. 27, 2019 USD ($) | Dec. 25, 2020 USD ($) | Dec. 27, 2019 USD ($) | Dec. 25, 2020 GBP (£) | Mar. 27, 2020 USD ($) | Mar. 27, 2020 GBP (£)
Pension Plan |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Company contributions | $ 249 | $ 235 | $ 736 | $ 698 |  |  |
Expected contributions in current fiscal year | 943 |  | $ 943 |  |  |  |
Other Defined Benefit Plan | Pension Promise |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Retirement age |  |  | 65 years |  |  |  |
Other assets, net | 1,112 |  | $ 1,112 |  | £ 827 | $ 975 | £ 866
Accrued retirement, other long-term liabilities | 1,112 |  | $ 1,112 |  | £ 827 | $ 975 | £ 866
Defined Contribution Plan |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Maximum employee contribution |  |  | 50.00% |  |  |  |
Employer matching contribution |  |  | 100.00% |  |  |  |
Maximum employer contribution |  |  | 5.00% |  |  |  |
Total contributions | 1,112 | 833 | $ 3,181 | 2,840 |  |  |
Defined Contribution Plan | AME Plan |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Total contributions | $ 207 | 201 | $ 592 | 560 |  |  |
Defined Contribution Plan | 401(K) Plan |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Maximum employee contribution |  |  | 35.00% |  |  |  |
Employer matching contribution |  |  | 100.00% |  |  |  |
Maximum employer contribution |  |  | 5.00% |  |  |  |
Total contributions |  | $ 376 |  | $ 1,310 |  |  |
Vesting percentage |  |  | 100.00% |  |  |  |
Safe Harbor Provision, employer contribution |  |  | 0.03 |  |  |  |

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