Annual report pursuant to Section 13 and 15(d)

Broadcast Licenses - Additional Information (Detail)

v3.20.4
Broadcast Licenses - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2020
Dec. 31, 2020
Dec. 31, 2019
Indefinite-lived Intangible Assets [Line Items]      
Impairment charge   $ 17,254 $ 2,925
Broadcast Licenses [Member]      
Indefinite-lived Intangible Assets [Line Items]      
License renewable term   8 years  
Percentage of fair value over carrying value benchmark for qualitative impairment analysis   25.00%  
Impairment charge $ 17,000    
Licensing Agreements [Member]      
Indefinite-lived Intangible Assets [Line Items]      
Finite-Lived Intangible Asset, Weighted Average Period before Next Renewal or Extension   6 years 6 months