Basis Of Presentation And Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Operating revenues	[1]	$ 489,358	$ 469,517		$ 932,993	$ 909,427
Television and Entertainment
Operating revenues		486,417	466,061	[2]	927,119	902,094	[2]
Advertising | Television and Entertainment
Operating revenues		311,431	312,864	[2]	581,870	604,571	[2]
Retransmission revenues | Television and Entertainment
Operating revenues		117,185	104,999	[2]	235,327	199,213	[2]
Carriage fees | Television and Entertainment
Operating revenues		40,815	31,867	[2]	82,477	65,477	[2]
Barter/trade | Television and Entertainment
Operating revenues	[3]	2,388	9,481	[2]	4,482	18,493	[2]
Other revenue | Television and Entertainment
Operating revenues		$ 14,598	$ 6,850	[2]	$ 22,963	$ 14,340	[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 and six months ended June 30, 2017, barter/trade revenue includes $7 million and $14 million of barter revenue, respectively.