Goodwill and Other Intangible Assets (Schedule Of Goodwill) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 798,037
Purchase accounting adjustments	8
Amortization of "second component" goodwill	(996)
Foreign currency translation	(14,815)
Ending balance	782,234
National Networks
Goodwill [Roll Forward]
Beginning balance	238,431
Purchase accounting adjustments	0
Amortization of "second component" goodwill	(996)
Foreign currency translation	0
Ending balance	237,435
International and Other
Goodwill [Roll Forward]
Beginning balance	559,606
Purchase accounting adjustments	8
Amortization of "second component" goodwill	0
Foreign currency translation	(14,815)
Ending balance	$ 544,799