LEASES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Finance leases	$ 0
Sub-lease income	0
Short-term lease expense	0
Right-of-use assets obtained in exchange for new operating lease liabilities, excluding amount recognized upon adoption of new accounting standard	47
Right-of-use assets obtained in exchange for new operating lease liabilities, upon adoption of new accounting standard	$ 282
Rental expense related to operating lease		$ 92	$ 102