STOCKHOLDERS' EQUITY - Treasury Stock Narrative (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Equity [Abstract]
Repurchase of common stock	$ 820	$ 725
Treasury stock purchased (in shares)	23,399,661

Number of shares that have been repurchased during the period and are being held in treasury.

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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration