STOCKHOLDERS' EQUITY - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Cost of stock repurchase	$ 1,220	$ 1,025	$ 820
Treasury stock purchased (in shares)	34,305,768	25,773,807
Treasury stock purchased, price per share (in dollars per share)	$ 35.56	$ 39.77
Deferred compensation, share-based payments
Class of Stock [Line Items]
Shares repurchased (in shares)	0	0