Segment Reporting (Summary Of The Operating Information) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Segment Reporting Information [Line Items]
Revenue	$ 1,442,232	$ 1,429,428	$ 1,431,061	$ 1,389,877	$ 1,365,664	$ 1,340,073	$ 1,367,727	$ 1,292,861	$ 5,692,598	$ 5,366,325	$ 5,142,272
Cost of revenues									1,071,041	937,348	854,091
Operating expenses									4,020,888	3,654,192	3,327,710
Total costs and expenses									5,091,929	4,591,540	4,181,801
Operating earnings									600,669	774,785	960,471
Domestic Segment [Member]
Segment Reporting Information [Line Items]
Revenue									5,038,127	4,730,266	4,575,171
Cost of revenues									967,035	827,904	755,729
Operating expenses									2,398,422	2,164,465	1,998,544
Total costs and expenses									3,365,457	2,992,369	2,754,273
Operating earnings									1,672,670	1,737,897	1,820,898
International Segment [Member]
Segment Reporting Information [Line Items]
Revenue									654,471	636,059	567,101
Cost of revenues									104,006	109,444	98,362
Operating expenses									276,914	321,116	264,196
Total costs and expenses									380,920	430,560	362,558
Operating earnings									273,551	205,499	204,543
Other
Segment Reporting Information [Line Items]
Operating expenses									1,345,552	1,168,611	1,064,970
Total costs and expenses									1,345,552	1,168,611	1,064,970
Operating earnings									$ (1,345,552)	$ (1,168,611)	$ (1,064,970)