GOODWILL, INDEFINITE-LIVED INTANGIBLE ASSETS AND OTHER INTANGIBLE ASSETS - Change in Carrying Amount of Goodwill (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in the carrying amount of goodwill related to continuing operations
Goodwill, net		$ 4,716,000,000	$ 2,124,000,000
Acquisitions			2,621,000,000
Assets held for sale		(9,000,000)	(29,000,000)
Impairment	$ (2,615,000,000)	(2,615,000,000)	0	$ 0
Goodwill, net		2,092,000,000	4,716,000,000	2,124,000,000
Indefinite-lived intangible assets		171,000,000	158,000,000	158,000,000
Consolidated VIEs
Change in the carrying amount of goodwill related to continuing operations
Indefinite-lived intangible assets		14,000,000	14,000,000
Broadcast
Change in the carrying amount of goodwill related to continuing operations
Goodwill, net		2,026,000,000	2,055,000,000
Acquisitions			0
Assets held for sale		(9,000,000)	(29,000,000)
Impairment		0
Goodwill, net		2,017,000,000	2,026,000,000	2,055,000,000
Indefinite-lived intangible assets		144,000,000	131,000,000	131,000,000
Local sports
Change in the carrying amount of goodwill related to continuing operations
Goodwill, net		2,615,000,000	0
Acquisitions			2,615,000,000
Assets held for sale		0	0
Impairment		(2,615,000,000)
Goodwill, net		0	2,615,000,000	0
Other
Change in the carrying amount of goodwill related to continuing operations
Goodwill, net		75,000,000	69,000,000
Acquisitions			6,000,000
Assets held for sale		0	0
Impairment		0
Goodwill, net		75,000,000	75,000,000	69,000,000
Indefinite-lived intangible assets		$ 27,000,000	$ 27,000,000	$ 27,000,000