NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenue Recognition, Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 1,622	$ 1,125	$ 771	$ 722	$ 894	$ 766	$ 730	$ 665	$ 4,240	$ 3,055	$ 2,636
Local News and Marketing Services
Disaggregation of Revenue [Line Items]
Revenue									2,655	2,715	2,394
Sports
Disaggregation of Revenue [Line Items]
Revenue									1,139	0	0
Other
Disaggregation of Revenue [Line Items]
Revenue									446	340	242
Distribution revenue
Disaggregation of Revenue [Line Items]
Revenue									2,500	1,299	1,140
Distribution revenue | Local News and Marketing Services
Disaggregation of Revenue [Line Items]
Revenue									1,341	1,186	1,033
Distribution revenue | Sports
Disaggregation of Revenue [Line Items]
Revenue									1,029	0	0
Distribution revenue | Other
Disaggregation of Revenue [Line Items]
Revenue									130	113	107
Advertising revenue
Disaggregation of Revenue [Line Items]
Revenue									1,480	1,559	1,369
Advertising revenue | Local News and Marketing Services
Disaggregation of Revenue [Line Items]
Revenue									1,268	1,484	1,315
Advertising revenue | Sports
Disaggregation of Revenue [Line Items]
Revenue									103	0	0
Advertising revenue | Other
Disaggregation of Revenue [Line Items]
Revenue									109	75	54
Other media and non-media revenues
Disaggregation of Revenue [Line Items]
Revenue									260	197	127
Other media and non-media revenues | Local News and Marketing Services
Disaggregation of Revenue [Line Items]
Revenue									46	45	46
Other media and non-media revenues | Sports
Disaggregation of Revenue [Line Items]
Revenue									7	0	0
Other media and non-media revenues | Other
Disaggregation of Revenue [Line Items]
Revenue									$ 207	$ 152	$ 81