Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Goodwill, Subsequent Recognition of Deferred Tax Asset	$ 656
Finite-Lived Intangible Assets, Amortization Expense	19,100	$ 18,100
National Networks [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill, Subsequent Recognition of Deferred Tax Asset	$ 656