SUPPLEMENTAL CASH FLOW DISCLOSURES ON NON-CASH ACTIVITIES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Barter revenues	$ 16,914	$ 19,365	$ 10,898
Barter expenses	16,741	19,324	9,440
Transition services costs incurred in the integration of CBS Radio	0	5,456	1,917
Reduction to the transition services asset	0	(5,456)	(1,917)
Financing Activities
Increase in paid-in capital from the issuance of RSUs	12,926	10,078	35,628
Decrease in paid-in capital from the forfeiture of RSUs	(1,753)	(1,228)	(1,117)
Net paid-in capital of RSUs issued (forfeited)	11,173	8,850	34,511
Dividend accrued on perpetual cumulative convertible preferred stock	0	0	0
Debt assumed in a business combination or merger	0	0	1,387,500
Investing Activities
Cash acquired through consolidation (deconsolidation) of a VIE	0	0	(302)
Noncash additions to property and equipment and intangibles	803	818	2,213
Net radio station assets given up in a market	22,795	0	124,500
Net radio station assets acquired in a market	22,500	0	124,500
Fair value of net assets acquired through the issuance of common stock	$ 0	$ 0	$ 1,168,848