Debt - Effect of Derivatives on Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2021	Jun. 28, 2020	Jun. 27, 2021	Jun. 28, 2020
Debt and Credit Arrangements
Total net interest expense on Consolidated Statements of Operations	$ (3,649)	$ (3,627)	$ (7,296)	$ (7,594)
Weighted average interest rates on debt, including the impact of interest rate swap agreements	3.20%	3.80%	3.20%	3.80%
Interest paid, including payments made or received under the swaps	$ 3,600	$ 4,000	$ 7,100	$ 8,100
Interest rate swap
Debt and Credit Arrangements
Portion of derivative liability that would be reclassified into earnings			9,800
Interest expense | Interest rate swap
Debt and Credit Arrangements
Amount of Gain or (Loss) Recognized in AOCI/AOCL on Derivative	1,399	(79)	2,781	(8,487)
Amount of Gain or (Loss) Reclassified from AOCI/AOCL into Income	(1,730)	(1,372)	(3,439)	(1,702)
Total net interest expense on Consolidated Statements of Operations	$ 3,649	$ 3,627	7,296	$ 7,594
Portion of derivative liability that would be reclassified into earnings			$ 7,100
Estimate of period of time over which portion of derivative liability would be reclassified into earnings			12 months