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Benefit Plans - Narrative (Details) $ in Thousands, £ in Millions |  | 3 Months Ended | 6 Months Ended | 9 Months Ended |
--- | --- | --- | --- | --- | ---
Apr. 06, 2020 USD ($) | Apr. 06, 2020 GBP (£) | Sep. 26, 2020 USD ($) | Jun. 27, 2020 USD ($) | Jun. 27, 2020 GBP (£) | Sep. 28, 2019 USD ($) | Dec. 31, 2021 USD ($) | Sep. 26, 2020 USD ($) | Sep. 28, 2019 USD ($) | Apr. 07, 2020 USD ($)
Defined Benefit Plan Disclosure |  |  |  |  |  |  |  |  |  |
Contributions expected |  |  | $ 2,300 |  |  |  |  | $ 2,300 |  |
Defined benefit plan expense |  |  | 983 |  |  | $ 573 |  | 2,617 | $ 1,697 |
Estimated decrease in pension cost |  |  |  |  |  |  |  |  |  | $ 36,000
Estimated percent reduction in pension costs |  |  |  |  |  |  |  |  |  | 30.00%
Benefit obligation, unamortized actuarial loss | $ 13,400 |  |  |  |  |  |  |  |  |
Cash contribution |  |  |  | $ 10,400 | £ 8.4 |  |  |  |  |
Pension and postretirement liability and reclassification adjustments |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure |  |  |  |  |  |  |  |  |  |
Benefit obligation, unamortized actuarial loss | £ |  | £ 10.9 |  |  |  |  |  |  |  |
Forecast | Minimum |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure |  |  |  |  |  |  |  |  |  |
Estimated settlement charge |  |  |  |  |  |  | $ 18,000 |  |  |
Forecast | Maximum |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure |  |  |  |  |  |  |  |  |  |
Estimated settlement charge |  |  |  |  |  |  | $ 22,000 |  |  |
Foreign Plan |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure |  |  |  |  |  |  |  |  |  |
Defined benefit plan expense |  |  | 500 |  |  | $ 200 |  | 1,500 | $ 600 |
Other comprehensive income as component of net period benefit cost, before tax |  |  | $ 200 |  |  |  |  | $ 500 |  |

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- Definition Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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- Definition Amount of payment to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(6) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 60 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39716-114964 + Details
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