Segment Reporting (Summary Of The Operating Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 1,431,061	$ 1,367,727	$ 2,820,938	$ 2,660,588
Cost of Revenue	268,673	238,783	521,877	470,061
Operating expenses	1,031,271	920,657	1,970,000	1,787,025
Total costs and expenses	1,299,944	1,159,440	2,491,877	2,257,086
Operating earnings (loss)	131,117	208,287	329,061	403,502
Domestic Segment
Segment Reporting Information [Line Items]
Revenues	1,266,112	1,202,064	2,496,942	2,337,160
Cost of Revenue	243,926	208,185	472,485	414,859
Operating expenses	605,636	551,468	1,177,654	1,071,339
Total costs and expenses	849,562	759,653	1,650,139	1,486,198
Operating earnings (loss)	416,550	442,411	846,803	850,962
International Segment [Member]
Segment Reporting Information [Line Items]
Revenues	164,949	165,663	323,996	323,428
Cost of Revenue	24,747	30,598	49,392	55,202
Operating expenses	73,258	73,407	141,427	142,551
Total costs and expenses	98,005	104,005	190,819	197,753
Operating earnings (loss)	66,944	61,658	133,177	125,675
Other
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operating expenses	352,377	295,782	650,919	573,135
Total costs and expenses	352,377	295,782	650,919	573,135
Operating earnings (loss)	$ (352,377)	$ (295,782)	$ (650,919)	$ (573,135)