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, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 1,512	$ 1,539	$ 1,283	$ 1,609	$ 1,622	$ 1,125	$ 771	$ 722	$ 5,943	$ 4,240	$ 3,055
Eliminations
Disaggregation of Revenue [Line Items]
Revenue									(116)	(59)	(10)
Broadcast | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									2,922	2,690	2,715
Local sports | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									2,686	1,139	0
Other | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									451	470	350
Distribution revenue
Disaggregation of Revenue [Line Items]
Revenue									4,085	2,500	1,299
Distribution revenue | Eliminations
Disaggregation of Revenue [Line Items]
Revenue									0	0	0
Distribution revenue | Broadcast | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									1,414	1,341	1,186
Distribution revenue | Local sports | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									2,472	1,029	0
Distribution revenue | Other | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									199	130	113
Advertising revenue
Disaggregation of Revenue [Line Items]
Revenue									1,689	1,480	1,559
Advertising revenue | Eliminations
Disaggregation of Revenue [Line Items]
Revenue									(2)	(1)	0
Advertising revenue | Broadcast | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									1,364	1,268	1,484
Advertising revenue | Local sports | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									196	103	0
Advertising revenue | Other | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									131	110	75
Other media, non-media, and intercompany revenue
Disaggregation of Revenue [Line Items]
Revenue									169	260	197
Other media, non-media, and intercompany revenue | Eliminations
Disaggregation of Revenue [Line Items]
Revenue									(114)	(58)	(10)
Other media, non-media, and intercompany revenue | Broadcast | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									144	81	45
Other media, non-media, and intercompany revenue | Local sports | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									18	7	0
Other media, non-media, and intercompany revenue | Other | Operating segments
Disaggregation of Revenue [Line Items]
Revenue									$ 121	$ 230	$ 162