REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended	4 Months Ended	6 Months Ended
May 01, 2019	Jun. 30, 2019	Jun. 30, 2020	May 01, 2019	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 277,388	$ 635,367	$ 487,249	$ 1,072,775	$ 1,267,418
Revenue from leases	286	279	399	696	864
Revenue, total	277,674	635,646	487,648	1,073,471	1,268,282
Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(757)	(1,121)	(1,947)	(2,568)	(3,925)
Revenue from leases	0	0	0	0	0
Revenue, total	(757)	(1,121)	(1,947)	(2,568)	(3,925)
Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	260,175	595,951	449,945	1,005,981	1,171,865
Revenue from leases	286	279	399	696	864
Revenue, total	260,461	596,230	450,344	1,006,677	1,172,729
Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	17,970	40,537	39,251	69,362	99,478
Revenue from leases	0	0	0	0	0
Revenue, total	17,970	40,537	39,251	69,362	99,478
Broadcast Radio
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	170,632	390,540	244,035	657,864	705,695
Broadcast Radio \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Broadcast Radio \| Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	170,632	390,540	244,035	657,864	705,695
Broadcast Radio \| Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Digital
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	26,840	64,238	93,227	102,789	186,003
Digital \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Digital \| Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	26,840	64,238	93,227	102,789	186,003
Digital \| Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Networks
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	50,889	105,426	96,330	189,088	230,907
Networks \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Networks \| Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	50,889	105,426	96,330	189,088	230,907
Networks \| Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Sponsorship and Events
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	10,617	31,790	14,809	50,330	44,157
Sponsorship and Events \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Sponsorship and Events \| Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	10,617	31,790	14,809	50,330	44,157
Sponsorship and Events \| Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Audio and Media Services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	17,269	39,528	37,472	67,037	95,888
Audio and Media Services \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(701)	(1,009)	(1,779)	(2,325)	(3,590)
Audio and Media Services \| Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0	0
Audio and Media Services \| Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	17,970	40,537	39,251	69,362	99,478
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,141	3,845	1,376	5,667	4,768
Other \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(56)	(112)	(168)	(243)	(335)
Other \| Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,197	3,957	1,544	5,910	5,103
Other \| Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0	$ 0