Prior Year Reclassifications (Summary Of Effect Of Reclassifications) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating, general and administrative expenses	$ 853,555	$ 852,330	$ 834,004
Income from operations	84,639	82,671	78,519
Other income (expense)	(3,049)	919	(2,094)
As Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating, general and administrative expenses		851,411	836,098
Income from operations		83,590	76,425
Reclassifications [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating, general and administrative expenses		919	(2,094)
Income from operations		(919)	2,094
Other income (expense)	$ (3,000)	$ 919	$ (2,094)