Segment Information (Summary Of Continuing Operations By Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Advertising									$ 1,083,975	$ 1,028,260	$ 820,336
Distribution									1,671,679	1,552,675	1,355,305
Consolidated revenues, net	$ 729,597	$ 634,646	$ 684,832	$ 706,579	$ 678,950	$ 632,165	$ 601,138	$ 668,682	2,755,654	2,580,935	2,175,641
Operating income (loss)	$ 103,728	$ 117,137	$ 178,032	$ 258,659	$ 160,344	$ 159,268	$ 158,834	$ 230,747	657,556	709,193	546,353
Share-based compensation expense									38,897	31,020	28,363
Restructuring expense									29,503	14,998	15,715
Impairment charges									67,805	0	0
Depreciation and amortization									(84,778)	(83,031)	(69,048)
Adjusted operating income									878,539	838,242	659,479
Capital expenditures									79,220	68,321	39,739
National Networks [Member]
Segment Reporting Information [Line Items]
Restructuring expense									8,516	3,194	3,664
International And Other [Member]
Segment Reporting Information [Line Items]
Restructuring expense									20,987	11,804	12,051
Operating Segments [Member] | National Networks [Member]
Segment Reporting Information [Line Items]
Advertising									990,508	945,288	764,610
Distribution									1,320,532	1,190,079	979,312
Consolidated revenues, net									2,311,040	2,135,367	1,743,922
Operating income (loss)									784,027	754,243	586,856
Share-based compensation expense									30,569	23,814	21,584
Restructuring expense									8,516	3,194	3,664
Impairment charges									0
Depreciation and amortization									(32,376)	(29,742)	(21,480)
Adjusted operating income									855,488	810,993	633,584
Capital expenditures									15,947	24,386	13,462
Operating Segments [Member] | International And Other [Member]
Segment Reporting Information [Line Items]
Advertising									94,467	82,972	55,726
Distribution									365,529	369,606	378,495
Consolidated revenues, net									459,996	452,578	434,221
Operating income (loss)									(120,914)	(42,542)	(41,977)
Share-based compensation expense									8,328	7,206	6,779
Restructuring expense									20,987	11,804	12,051
Impairment charges									67,805
Depreciation and amortization									(52,402)	(53,289)	(47,568)
Adjusted operating income									28,608	29,757	24,421
Capital expenditures									63,273	43,935	26,277
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Advertising									(1,000)	0	0
Distribution									(14,382)	(7,010)	(2,502)
Consolidated revenues, net									(15,382)	(7,010)	(2,502)
Operating income (loss)									(5,557)	(2,508)	1,474
Share-based compensation expense									0	0	0
Restructuring expense									0	0	0
Impairment charges									0
Depreciation and amortization									0	0	0
Adjusted operating income									(5,557)	(2,508)	1,474
Capital expenditures									0	0	0
Intersegment Eliminations [Member] | National Networks [Member]
Segment Reporting Information [Line Items]
Consolidated revenues, net									(14,963)	(6,719)	(1,802)
Intersegment Eliminations [Member] | International And Other [Member]
Segment Reporting Information [Line Items]
Consolidated revenues, net									$ (419)	$ (291)	$ (700)