Annual report pursuant to Section 13 and 15(d)

Broadcast Licenses - Schedule of Changes in Broadcasting Licenses (Detail)

v3.20.4
Broadcast Licenses - Schedule of Changes in Broadcasting Licenses (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Indefinite-lived Intangible Assets [Line Items]    
Balance, beginning of period before cumulative loss on impairment $ 441,143 $ 484,691
Accumulated loss on impairment, Beginning Balance (103,285) (108,375)
Balance, beginning of period after cumulative loss on impairment 337,858 376,316
Impairments based on the estimated fair value of broadcast licenses (16,994) (2,908)
Balance, end of period before cumulative loss on impairment 440,052 441,143
Accumulated loss on impairment, Ending Balance (120,279) (103,285)
Balance, end of period after cumulative loss on impairment 319,773 337,858
Radio Stations [Member]    
Indefinite-lived Intangible Assets [Line Items]    
Acquisitions of FM translators and construction permits   617
Disposition of radio stations and FM translators $ (1,091) (36,502)
FM Translators [Member]    
Indefinite-lived Intangible Assets [Line Items]    
Acquisitions of FM translators and construction permits   35
Capital Projects [Member]    
Indefinite-lived Intangible Assets [Line Items]    
Acquisitions of FM translators and construction permits   $ 300