Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 701,980
Impairment charge	(25,062)
Amortization of "second component" goodwill	(996)
Foreign currency translation	(2,112)
Ending balance	673,810
National Networks
Goodwill [Roll Forward]
Beginning balance	237,103
Impairment charge	0
Amortization of "second component" goodwill	(996)
Foreign currency translation	0
Ending balance	236,107
International and Other
Goodwill [Roll Forward]
Beginning balance	464,877
Impairment charge	(25,062)
Amortization of "second component" goodwill	0
Foreign currency translation	(2,112)
Ending balance	$ 437,703