Reconciliation of Total Segment Profit to Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Profit	$ 95,513	$ 65,806	$ 267,741	$ 205,272
Amortization	11,051	10,974	33,003	33,325
Unallocated General And Administrative Expenses	23,807	20,160	64,073	61,316
Operating income	60,655	34,672	170,665	110,631
Interest expense	7,749	9,468	24,418	27,778
Interest income	(150)	(123)	(323)	(233)
Other income, net	2,906	(565)	3,762	(2,294)
Income before income tax expense	$ 50,150	$ 25,892	$ 142,808	$ 85,380