OTHER ASSETS - Equity Investments and Other Investments (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended	3 Months Ended		9 Months Ended
	Nov. 18, 2020	Apr. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments			$ 12	$ (10)	$ 23	$ (23)
Investments in equity securities measured at fair value			509		509		$ 400
Fair value adjustment gains (losses) on investments measured at fair value and NAV			(2)	(1)	60	(3)
Equity investments, net of cumulative impairment			27		27		26
Cumulative impairment			7		7		7
Impairment recorded			0	0	0	0
Incremental investment					244	85
Fair Value Measured at Net Asset Value Per Share
Schedule of Equity Method Investments [Line Items]
Investments measured at NAV			142		142		$ 24
Unfunded commitments related to investments valued using NAV practical expedient			55		55
YES Network
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments			$ 10	$ (3)	$ 29	$ 3
Bally's
Schedule of Equity Method Investments [Line Items]
Penny warrants acquirable (up to) (in shares)	8.2
Number of penny warrants exercisable (in shares)	3.3
Options available to purchase (up to) (in shares)	1.6
Option purchase price, minimum (in USD per share)	$ 30
Option purchase price, maximum (in USD per share)	$ 45
Vesting period	4 years
Incremental investment		$ 93
Number of warrants convertible (in shares)		1.7
Exercise price (in USD per share)		$ 0.01