Basis Of Presentation And Significant Accounting Policies Disaggregated Revenue (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Operating revenues	[1]	$ 443,635	$ 439,910
Television and Entertainment
Operating revenues		440,702	436,033	[2]
Advertising | Television and Entertainment
Operating revenues		270,439	291,707	[2]
Retransmission revenues | Television and Entertainment
Operating revenues		118,142	94,214	[2]
Carriage fees | Television and Entertainment
Operating revenues		41,662	33,610	[2]
Barter/trade | Television and Entertainment
Operating revenues	[3]	2,094	9,012	[2]
Other revenue | Television and Entertainment
Operating revenues		$ 8,365	$ 7,490	[2]

[1] (1)See Note 2 for the disclosures of operating revenues and operating loss included in discontinued operations for the historical periods.

[2] (1)Prior period amounts have not been adjusted under the modified retrospective method.

[3] (2)For the three months ended March 31, 2017, barter/trade revenue includes $7 million of barter revenue.