Basis Of Presentation And Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Total operating revenues	$ 454,988	$ 443,635
Television and Entertainment
Total operating revenues	453,427	440,702
Advertising revenue | Television and Entertainment
Total operating revenues	269,889	270,439
Retransmission revenues | Television and Entertainment
Total operating revenues	132,860	118,142
Carriage fees | Television and Entertainment
Total operating revenues	41,139	41,662
Other | Television and Entertainment
Total operating revenues	$ 9,539	$ 10,459