Annual report pursuant to Section 13 and 15(d)

Goodwill - Schedule of Changes in Goodwill (Detail)

v3.20.4
Goodwill - Schedule of Changes in Goodwill (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Goodwill [Line Items]    
Balance, beginning of period before cumulative loss on impairment $ 28,454 $ 28,818
Accumulated loss on impairment (4,456) (2,029)
Balance, beginning of period after cumulative loss on impairment 23,998 26,789
Impairments based on the estimated fair value goodwill (307) (2,427)
Balance, end of period before cumulative loss on impairment 28,520 28,454
Accumulated loss on impairment (4,763) (4,456)
Ending period balance 23,757 23,998
Radio Stations [Member]    
Goodwill [Line Items]    
Goodwill, Written off Related to Sale of Business Unit   (29)
Digital Media [Member]    
Goodwill [Line Items]    
Acquisitions $ 66 6
Goodwill, Written off Related to Sale of Business Unit   $ (341)