Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill, Subsequent Recognition of Deferred Tax Asset	$ 1,328	$ 2,544
Amortization of Intangible Assets	$ 43,000	47,100	$ 38,600
Percentage Of Hypothetical Decrease	20.00%
National Networks [Member]
Goodwill [Line Items]
Goodwill, Subsequent Recognition of Deferred Tax Asset	$ 1,328	2,544
International And Other [Member]
Goodwill [Line Items]
Goodwill, Subsequent Recognition of Deferred Tax Asset	$ 0	0
Hypothetical Decrease, Fair Value of Reporting Unit	6.00%
Accelerated Amortization of Intangible Assets		$ 9,000