Debt - Effect of Derivatives on Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jun. 25, 2017	Jul. 01, 2018	Jun. 25, 2017
Debt and Credit Arrangements
Weighted average interest rates on debt, including impact of interest rate swaps	3.60%	2.30%	3.60%	2.30%
Interest paid, including payments made or received under the swaps	$ 5,800	$ 2,100	$ 10,700	$ 3,900
Interest rate swap
Debt and Credit Arrangements
Interest rate swap assets	10,200		10,200
Interest expense | Interest rate swap
Debt and Credit Arrangements
Amount of Gain or (Loss) Recognized in AOCI/AOCL on Derivative	2,207	(1,170)	7,380	(1,465)
Amount of Gain or (Loss) Reclassified from AOCI/AOCL into Income	(89)	(126)	(197)	(324)
Total Interest Expense on Consolidated Statements of Income	$ (5,911)	$ (1,894)	$ (11,131)	$ (3,840)
Estimate of period of time over which portion of derivative liability would be reclassified into earnings			12 months
Portion of derivative asset that would be reclassified into earnings			$ 2,400