Debt and Credit Arrangements - Effect of Derivatives on Financial Statements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Debt and Credit Arrangements
Total Net interest expense on Consolidated Statements of Operations	$ (20,593)	$ (25,673)	$ (11,283)
Weighted average interest rates on debt, including the impact of interest rate swap agreements	4.10%	3.90%	2.70%
Interest paid, including payments made or received under the swaps	$ 18,100	$ 23,500	$ 10,800
Interest rate swap
Debt and Credit Arrangements
Portion of derivative liability that would be reclassified into earnings	6,200
Interest expense | Interest rate swap
Debt and Credit Arrangements
Amount of Gain or (Loss) Recognized in AOCI/AOCL on Derivative	(8,303)	3,222	891
Amount of Gain or (Loss) Reclassified from AOCI/AOCL into Income	660	(22)	(421)
Total Net interest expense on Consolidated Statements of Operations	(20,593)	$ (25,673)	$ (11,283)
Portion of derivative liability that would be reclassified into earnings	$ 2,300
Estimate of period of time over which portion of derivative liability would be reclassified into earnings	12 months