REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 927,747	$ 743,829	$ 2,495,188	$ 2,011,248
Revenue from leases	304	577	1,133	1,440
Revenue, total	928,051	744,406	2,496,321	2,012,688
Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(2,775)	(1,930)	(10,047)	(5,855)
Revenue from leases	0	0	0	0
Revenue, total	(2,775)	(1,930)	(10,047)	(5,855)
Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	658,675	554,520	1,761,593	1,540,383
Revenue from leases	304	577	1,133	1,440
Revenue, total	658,979	555,097	1,762,726	1,541,823
Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	205,769	116,200	561,252	302,203
Revenue from leases	0	0	0	0
Revenue, total	205,769	116,200	561,252	302,203
Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	66,078	75,039	182,390	174,517
Revenue from leases	0	0	0	0
Revenue, total	66,078	75,039	182,390	174,517
Broadcast Radio
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	483,456	404,460	1,293,134	1,110,155
Broadcast Radio \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Broadcast Radio \| Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	483,456	404,460	1,293,134	1,110,155
Broadcast Radio \| Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Broadcast Radio \| Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Networks
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	127,920	118,982	366,592	349,889
Networks \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Networks \| Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	127,920	118,982	366,592	349,889
Networks \| Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Networks \| Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Sponsorship and Events
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	42,663	28,898	93,641	73,055
Sponsorship and Events \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Sponsorship and Events \| Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	42,663	28,898	93,641	73,055
Sponsorship and Events \| Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Sponsorship and Events \| Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Digital, excluding Podcast
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	140,098	93,574	400,729	242,479
Digital, excluding Podcast \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(1,475)	0	(4,547)	0
Digital, excluding Podcast \| Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Digital, excluding Podcast \| Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	141,573	93,574	405,276	242,479
Digital, excluding Podcast \| Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Podcast
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	64,196	22,626	155,976	59,724
Podcast \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Podcast \| Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Podcast \| Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	64,196	22,626	155,976	59,724
Podcast \| Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Audio and Media Services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	64,890	73,277	177,337	169,165
Audio and Media Services \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(1,188)	(1,762)	(5,053)	(5,352)
Audio and Media Services \| Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Audio and Media Services \| Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Audio and Media Services \| Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	66,078	75,039	182,390	174,517
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4,524	2,012	7,779	6,781
Other \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(112)	(168)	(447)	(503)
Other \| Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4,636	2,180	8,226	7,284
Other \| Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Other \| Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0