v3.19.3
INTANGIBLE ASSETS AND GOODWILL - Changes in goodwill (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2019
Dec. 31, 2018
Dec. 31, 2017
Goodwill [Line Items]        
Goodwill before cumulative loss on impairment $ 982,663   $ 982,663 $ 988,056
Accumulated loss on impairment 443,194   443,194 $ 126,056
Beginning balance after cumulative loss on impairment   $ 539,469 862,000  
Loss on impairment during the year (317,100) 0 (317,138)  
Measurement period adjustments to acquired goodwill   0 (21,498)  
Ending balance $ 539,469 549,881 539,469  
Cumulus Exchange [Member]        
Goodwill [Line Items]        
Disposition of radio stations   (4,862) (8,623)  
Cumulus Exchange [Member]        
Goodwill [Line Items]        
Acquisition of rasdio stations   $ 15,274 $ 24,728