INTANGIBLE ASSETS AND GOODWILL - Assumption of impairment (Details) - Broadcasting Licenses	3 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Jun. 30, 2017
Estimates and assumptions used for impairment test [Line Items]
Discount rate	8.00%	8.50%	9.00%	9.00%	9.25%
Minimum
Estimates and assumptions used for impairment test [Line Items]
Operating profit margin ranges expected for average stations in the markets where the Company operates	22.00%	18.00%	22.00%	22.00%	19.00%
Forecasted growth rate (including long-term growth rate) range of the Company's markets	0.00%	0.00%	0.00%	0.50%	1.00%
Maximum
Estimates and assumptions used for impairment test [Line Items]
Operating profit margin ranges expected for average stations in the markets where the Company operates	36.00%	36.00%	37.00%	37.00%	40.00%
Forecasted growth rate (including long-term growth rate) range of the Company's markets	0.80%	0.80%	0.90%	1.00%	2.00%