Annual report pursuant to Section 13 and 15(d)

Broadcast Licenses - Carrying Value and Fair Value of Broadcast Licenses (Detail)

v3.19.1
Broadcast Licenses - Carrying Value and Fair Value of Broadcast Licenses (Detail) - Broadcast Licenses [Member]
 12 Months Ended
Dec. 31, 2018
USD ($)
Accounting
Less than or equal to 25% [Member]  
Indefinite-lived Intangible Assets [Line Items]  
Number of accounting units | Accounting 9
Broadcast license carrying value | $ $ 200,098,000
>26%-50% [Member]  
Indefinite-lived Intangible Assets [Line Items]  
Number of accounting units | Accounting 1
Broadcast license carrying value | $ $ 14,743,000
>26%-50% [Member] | Station Operating Income [Member]  
Indefinite-lived Intangible Assets [Line Items]  
Number of accounting units | Accounting 2
Broadcast license carrying value | $ $ 7,692,000
>51% to 75% [Member]  
Indefinite-lived Intangible Assets [Line Items]  
Number of accounting units | Accounting 4
Broadcast license carrying value | $ $ 52,051,000
> than 76% [Member]  
Indefinite-lived Intangible Assets [Line Items]  
Number of accounting units | Accounting 2
Broadcast license carrying value | $ $ 9,558,000
> than 76% [Member] | Station Operating Income [Member]  
Indefinite-lived Intangible Assets [Line Items]  
Number of accounting units | Accounting 14
Broadcast license carrying value | $ $ 95,039,000