REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 861,260	$ 487,249	$ 1,567,441	$ 1,267,418
Revenue from leases	345	399	829	864
Revenue, total	861,605	487,648	1,568,270	1,268,282
Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(3,350)	(1,947)	(7,272)	(3,925)
Revenue from leases	0	0	0	0
Revenue, total	(3,350)	(1,947)	(7,272)	(3,925)
Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	605,505	356,718	1,102,918	985,862
Revenue from leases	345	399	829	864
Revenue, total	605,850	357,117	1,103,747	986,726
Digital Audio Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	197,930	93,227	355,483	186,003
Revenue from leases	0	0	0	0
Revenue, total	197,930	93,227	355,483	186,003
Audio & Media Services Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	61,175	39,251	116,312	99,478
Revenue from leases	0	0	0	0
Revenue, total	61,175	39,251	116,312	99,478
Broadcast Radio
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	451,142	244,035	809,678	705,695
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	451,142	244,035	809,678	705,695
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	123,586	96,330	238,672	230,907
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	123,586	96,330	238,672	230,907
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	28,585	14,809	50,978	44,157
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	28,585	14,809	50,978	44,157
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	143,324	71,984	260,631	148,905
Digital, excluding Podcast \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(1,178)	0	(3,072)	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	144,502	71,984	263,703	37,098
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	53,428	21,243	91,780	37,098
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	53,428	21,243	91,780	148,905
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	59,171	37,472	112,447	95,888
Audio and Media Services \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(2,004)	(1,779)	(3,865)	(3,590)
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	61,175	39,251	116,312	99,478
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,024	1,376	3,255	4,768
Other \| Eliminations
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	(168)	(168)	(335)	(335)
Other \| Multiplatform Group \| Operating segments
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,192	1,544	3,590	5,103
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