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, 2018	May 01, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 277,388	$ 635,367	$ 891,132	$ 1,072,775	$ 1,663,014
Revenue from leases	286	279	632	696	1,522
Revenue, total	277,674	635,646	891,764	1,073,471	1,664,536
Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(757)	(1,121)	(1,601)	(2,568)	(3,273)
Revenue from leases	0	0	0	0	0
Revenue, total	(757)	(1,121)	(1,601)	(2,568)	(3,273)
Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	260,175	595,951	831,316	1,005,981	1,555,528
Revenue from leases	286	279	632	696	1,522
Revenue, total	260,461	596,230	831,948	1,006,677	1,557,050
Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	17,970	40,537	61,417	69,362	110,759
Revenue from leases	0	0	0	0	0
Revenue, total	17,970	40,537	61,417	69,362	110,759
Broadcast Radio
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	170,632	390,540	568,968	657,864	1,059,111
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	568,968	657,864	1,059,111
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	26,784	64,106	68,574	102,566	127,941
Digital \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(56)	(132)	0	(223)	0
Digital \| Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	26,840	64,238	68,574	102,789	127,941
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	146,981	189,088	279,032
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	146,981	189,088	279,032
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	41,256	50,330	79,148
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	41,256	50,330	79,148
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	39,548	59,816	67,017	107,486
Audio and Media Services \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(701)	(989)	(1,601)	(2,345)	(3,273)
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	61,417	69,362	110,759
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,197	3,957	5,537	5,910	10,296
Other \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Other \| Audio \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,197	3,957	5,537	5,910	10,296
Other \| Audio and Media Services \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0