Debt - Effect of Derivatives on Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Debt and Credit Arrangements
Weighted average interest rates on debt, including the impact of interest rate swap agreements	3.80%	3.80%	3.80%	4.20%
Interest paid, including payments made or received under the swaps	$ 3,900	$ 3,000	$ 12,000	$ 14,100
Interest rate swap
Debt and Credit Arrangements
Portion of derivative liability that would be reclassified into earnings			15,300
Interest expense | Interest rate swap
Debt and Credit Arrangements
Amount of Gain or (Loss) Recognized in AOCI/AOCL on Derivative	1,268	(1,437)	(7,219)	(9,641)
Amount of Gain or (Loss) Reclassified from AOCI/AOCL into Income	(1,674)	161	(3,376)	849
Total Net interest expense on Condensed Consolidated Statements of Operations	$ (3,636)	$ (4,249)	(11,230)	$ (14,797)
Portion of derivative liability that would be reclassified into earnings			$ 7,200
Estimate of period of time over which portion of derivative liability would be reclassified into earnings			12 months