Intangible Assets (Narrative) (Detail)	6 Months Ended	12 Months Ended
	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) geographical_market	Dec. 31, 2019 USD ($)
Intangible Assets And Goodwill [Line Items]
Amortization expense, definite-lived		$ 19,738,000	$ 24,657,000
Impairment of intangible assets			16,700,000
License agreements		$ 825,590,000	830,490,000
Number of geographical markets | geographical_market		86
Impairment of Intangible Assets
Intangible Assets And Goodwill [Line Items]
Impairment of intangible assets			15,600,000
Trademarks
Intangible Assets And Goodwill [Line Items]
Impairment of intangible assets		$ 0	0
Broadcast Licenses
Intangible Assets And Goodwill [Line Items]
Impairment of intangible assets		0
FCC Licenses, 4 Geographic Market
Intangible Assets And Goodwill [Line Items]
License agreements		$ 43,700,000
Number of geographical markets | geographical_market		4
FCC licenses
Intangible Assets And Goodwill [Line Items]
Impairment of intangible assets	$ 4,500,000	$ 4,509,000	$ 15,563,000