Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Pension Benefits - Multi-Employer Defined Benefit Pension Plan (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 28, 2020	Jun. 27, 2020	Jun. 29, 2019
Benefit payments
Employer contributions	$ 0		$ 0
Multi-Employer Defined Benefit Pension Plan
Contribution to the multi-employer plan		$ 400	$ 500
Maximum contribution to multi-employer plan (as a percent)		5.00%
Plan \| Minimum
Multi-Employer Defined Benefit Pension Plan
Maximum contribution to multi-employer plan (as a percent)		5.00%