ACQUISITIONS AND DISPOSITIONS (Details Textual) - USD ($)		1 Months Ended				3 Months Ended
	Aug. 03, 2017	May 02, 2017	Apr. 28, 2017	Apr. 20, 2017	Jan. 30, 2017	Jun. 30, 2017	Mar. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Proceeds from Divestiture of Businesses	$ 2,000,000				$ 25,000,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Customer Relationship			$ 1,400,000
Sale Leaseback Transaction, Net Proceeds, Investing Activities		$ 25,000,000
Sale And Leaseback Transaction Gain		$ 22,500,000
Sale and Leaseback Transaction, Gain (Loss), Net						$ 14,400,000
Goodwill			4,600,000				$ 260,182,000	$ 262,894,000
Sale Leaseback Transaction, Deferred Gain, Net						$ 8,100,000
Red Zebra Broadcasting [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment, Total				$ 206,000
Business Acquisition Purchase Price Allocation Indefinite Lived Intangible Assets, Radio Broadcasting Licenses				1,600,000
Business Acquisition Purchase Price Allocation Indefinite Lived Intangible Assets Including Goodwill				47,000
Business Combination, Consideration Transferred				2,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Intangible Assets				$ 114,000
Moguldom Media Group, LLC. [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment, Total			22,000
Business Combination, Consideration Transferred			5,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Intangible Assets			322,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Brand and Trade Names			1,200,000
Business Combination, Contingent Consideration, Liability			2,200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other			263,000
Goodwill			$ 5,000,000