INCOME TAXES - Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current
-U.S. Federal	$ 9	$ (272)	$ (169)
-U.S. State	(41)	(57)	(94)
-Non-U.S.	(78)	(161)	(284)
Current income tax expense	(110)	(490)	(547)
Deferred
-U.S. Federal	180	141	10
-U.S. State	81	39	(6)
-Non-U.S.	48	(16)	105
Deferred income tax expense	309	164	109
Provision for income taxes	$ 199	$ (326)	$ (438)