Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,093,520	$ 563,427
Less: accumulated depreciation	(359,382)	(287,274)
Property and equipment, net	734,138	276,153
Buildings and improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 225,183	$ 81,337
Estimated useful life	39 years	39 years
Land [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 127,625	$ 32,068
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	29,114	9,909
Studio and transmission equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 539,788	$ 363,574
Studio and transmission equipment [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life	5 years	5 years
Studio and transmission equipment [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life	15 years	15 years
Computer equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 96,487	$ 40,255
Computer equipment [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life	3 years	3 years
Computer equipment [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life	5 years	5 years
Furniture And Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 18,876	$ 11,516
Estimated useful life	7 years	7 years
Vehicles [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 35,211	$ 17,340
Estimated useful life	5 years	5 years
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 21,236	$ 7,428