Annual report pursuant to Section 13 and 15(d)

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

v3.19.1
Broadcast Licenses - Schedule of Changes in Broadcasting Licenses (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Indefinite-lived Intangible Assets [Line Items]    
Balance, beginning of period before cumulative loss on impairment $ 486,455 $ 494,058
Accumulated loss on impairment, Beginning Balance (105,541) (105,541)
Balance, beginning of period after cumulative loss on impairment 380,914 388,517
Capital projects to improve broadcast signal and strength   5
Abandoned capital projects (40)  
Impairments based on the estimated fair value of broadcast licenses (2,834)  
Balance, end of period before cumulative loss on impairment 484,691 486,455
Accumulated loss on impairment, Ending Balance (108,375) (105,541)
Balance, end of period after cumulative loss on impairment 376,316 380,914
Radio Stations [Member]    
Indefinite-lived Intangible Assets [Line Items]    
Acquisitions of FM translators and construction permits 6,270 191
Disposition of radio stations (8,013) (7,997)
FM Translators [Member]    
Indefinite-lived Intangible Assets [Line Items]    
Acquisitions of FM translators and construction permits $ 19 $ 198