SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property, Plant and Equipment (Narrative) (Details)	12 Months Ended
	Dec. 31, 2019
Buildings and improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimate useful lives	10 years
Buildings and improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimate useful lives	39 years
Towers, transmitters and studio equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimate useful lives	5 years
Towers, transmitters and studio equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimate useful lives	40 years
Furniture and other equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimate useful lives	3 years
Furniture and other equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimate useful lives	7 years