Cash And Cash Equivalents And Advertising Accounting Policies (Effect Of Reclassification Of Consolidated Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Accounts receivable and prepaid expenses	$ (2,118)	$ 10,264
Net cash provided by operating activities	112,062	95,840
Net increase (decreases) in cash and cash equivalents	(9,605)	(4,382)
Cash and cash equivalents at beginning of year	47,917	46,818
Cash and cash equivalents at end of period	38,312	42,436
As Previously Reported [Member]
Accounts receivable and prepaid expenses		20,147
Net cash provided by operating activities		105,723
Net increase (decreases) in cash and cash equivalents		5,501
Cash and cash equivalents at beginning of year	21,305	14,653
Cash and cash equivalents at end of period		20,154
Reclassifications [Member]
Accounts receivable and prepaid expenses		(9,883)
Net cash provided by operating activities		(9,883)
Net increase (decreases) in cash and cash equivalents		(9,883)
Cash and cash equivalents at beginning of year	$ 26,612	32,165
Cash and cash equivalents at end of period		$ 22,282