Benefit Plans - Assets of the Plan Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Details) $ in Thousands	12 Months Ended
	Dec. 28, 2019 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ 164,603
Ending balance	183,486
Pension Plan [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	164,603
Ending balance	183,486
Pension Plan [Member] | Limited Partner [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Redemptions	(3,825)
Subscriptions	6,846
Net appreciation in fair value	(134)
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	5,028
Ending balance	7,915
Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member] | Limited Partner [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	5,028
Ending balance	$ 7,915