FAIR VALUE MEASUREMENTS - Notional Amount of Foreign Currency Exchange Derivatives (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Recurring Basis
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Assets at fair value	$ 14,171	$ 10,751
Recurring Basis | Level 2
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Assets at fair value	503	2,945
Foreign currency exchange derivatives | Not Designated as Hedging Instrument | Foreign currency purchases
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount	939	1,770
Foreign currency exchange derivatives | Not Designated as Hedging Instrument | Foreign currency sales
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount	1,008	901
Foreign currency exchange derivatives | Not Designated as Hedging Instrument | Recurring Basis
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Assets at fair value	10	12
Liabilities at fair value	13	5
Foreign currency exchange derivatives | Not Designated as Hedging Instrument | Recurring Basis | Level 2
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Assets at fair value	10	12
Liabilities at fair value	$ 13	$ 5