BUSINESS COMBINATIONS - Purchase Price Allocation (Details) - USD ($) $ in Thousands			12 Months Ended
	Oct. 16, 2019	May 09, 2019	Dec. 31, 2019	Jul. 19, 2019	Dec. 31, 2018	Sep. 27, 2018	Apr. 30, 2018	Dec. 31, 2017	Nov. 17, 2017
Business Acquisition [Line Items]
Goodwill			$ 43,920		$ 539,469			$ 862,000
Jerry Lee
Business Acquisition [Line Items]
Property, plant and equipment						$ 981
Goodwill						24,396
Net working capital						3,234
Total intangible and other assets						55,453
Assets						56,434
Preliminary fair value of net assets acquired						56,434
Emmis
Business Acquisition [Line Items]
Property, plant and equipment							$ 1,558
Goodwill							332
Total intangible and other assets							13,442
Assets							15,000
Preliminary fair value of net assets acquired							15,000
Pineapple Street Media
Business Acquisition [Line Items]
Accounts receivable				$ 997
Indefinite-lived intangible assets acquired				1,793
Goodwill				12,445
Total intangible and other assets				15,235
Assets				15,235
Unearned revenue				238
Accounts payable				30
Total liabilities				268
Preliminary fair value of net assets acquired				$ 14,967
Cadence 13
Business Acquisition [Line Items]
Property, plant and equipment	$ 654
Operating lease right-of-use asset	62
Deferred tax asset	2,900
Goodwill	31,392
Net working capital	(757)
Total intangible and other assets	40,331
Operating lease liabilities	(985)
Preliminary fair value of net assets acquired	$ 39,243
2019 Cumulus Exchange
Business Acquisition [Line Items]
Property, plant and equipment		$ 844
Indefinite-lived intangible assets acquired		19,576
Goodwill		2,080
Total intangible and other assets		21,656
Assets		22,500
Preliminary fair value of net assets acquired		$ 22,500
Minimum | Cadence 13
Business Acquisition [Line Items]
Useful life	3 years
Minimum | 2019 Cumulus Exchange
Business Acquisition [Line Items]
Useful life		3 years
Maximum
Business Acquisition [Line Items]
Useful life			40 years
Maximum | Cadence 13
Business Acquisition [Line Items]
Useful life	7 years
Maximum | 2019 Cumulus Exchange
Business Acquisition [Line Items]
Useful life		7 years
Advertising contracts | Jerry Lee
Business Acquisition [Line Items]
Finite-lived intangible assets acquired						477
Advertising contracts | Emmis
Business Acquisition [Line Items]
Finite-lived intangible assets acquired							114
Advertiser relationships | Emmis
Business Acquisition [Line Items]
Finite-lived intangible assets acquired							207
Other noncurrent assets | Emmis
Business Acquisition [Line Items]
Finite-lived intangible assets acquired							4
Trademarks and Trade Names | Cadence 13
Business Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 5,977
Finite-lived intangible assets acquired, useful life	3 years
Radio broadcasting licenses | Jerry Lee
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired						$ 27,346
Radio broadcasting licenses | Emmis
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired							$ 12,785
Assets Acquired | Beasley Transaction
Business Acquisition [Line Items]
Property, plant and equipment									$ 667
Indefinite-lived intangible assets acquired									36,233
Goodwill									289
Additional cash consideration									12,000
Preliminary fair value of net assets acquired									48,900
Assets Acquired | iHeartMedia Transaction
Business Acquisition [Line Items]
Property, plant and equipment									13,725
Indefinite-lived intangible assets acquired									63,627
Goodwill									11,700
Preliminary fair value of net assets acquired									71,300
Assets Acquired | Advertising contracts | iHeartMedia Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									265
Assets Acquired | Advertiser relationships | iHeartMedia Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									1,041
Assets Acquired | Sports rights agreement | Beasley Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									0
Assets Acquired | Radio broadcasting licenses | Beasley Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									35,944
Assets Acquired | Radio broadcasting licenses | iHeartMedia Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									50,621
Assets Disposed | Beasley Transaction
Business Acquisition [Line Items]
Property, plant and equipment									807
Indefinite-lived intangible assets acquired									48,093
Goodwill									11,882
Additional cash consideration									0
Preliminary fair value of net assets acquired									48,900
Assets Disposed | iHeartMedia Transaction
Business Acquisition [Line Items]
Property, plant and equipment									8,149
Indefinite-lived intangible assets acquired									63,151
Goodwill									6,852
Preliminary fair value of net assets acquired									71,300
Assets Disposed | Advertising contracts | iHeartMedia Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									0
Assets Disposed | Advertiser relationships | iHeartMedia Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									0
Assets Disposed | Sports rights agreement | Beasley Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									267
Assets Disposed | Radio broadcasting licenses | Beasley Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									35,944
Assets Disposed | Radio broadcasting licenses | iHeartMedia Transaction
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired									56,299
Unfavorable lease agreements assumed | Assets Acquired | iHeartMedia Transaction
Business Acquisition [Line Items]
Operating lease liabilities									(1,301)
Unfavorable lease agreements assumed | Assets Disposed | iHeartMedia Transaction
Business Acquisition [Line Items]
Operating lease liabilities			$ 0
Deferred tax liabilities | iHeartMedia Transaction
Business Acquisition [Line Items]
Deferred tax liabilities									4,751
Deferred tax liabilities | Assets Disposed | iHeartMedia Transaction
Business Acquisition [Line Items]
Deferred tax liabilities									$ 0