Quarterly report pursuant to Section 13 or 15(d)

Goodwill - Schedule of Changes in Goodwill (Detail)

v3.21.2
Goodwill - Schedule of Changes in Goodwill (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Goodwill [Line Items]        
Balance, beginning of period before cumulative loss on impairment   $ 28,520 $ 28,454 $ 28,454
Accumulated loss on impairment   (4,763) (4,456) (4,456)
Balance, beginning of period after cumulative loss on impairment   23,757 23,998 23,998
Impairments based on the estimated fair value goodwill $ 0 0 $ (307) (307)
Balance, end of period before cumulative loss on impairment 28,749 28,749   28,520
Accumulated loss on impairment (4,763) (4,763)   (4,763)
Ending period balance $ 23,986 23,986   23,757
Radio Stations [Member]        
Goodwill [Line Items]        
Acquisitions   4   $ 66
Digital Media [Member]        
Goodwill [Line Items]        
Acquisitions   $ 225