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FAIR VALUE MEASUREMENTS - Notional Amount of Foreign Currency Exchange Derivatives (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended			6 Months Ended
	Apr. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gains (losses) on foreign currency exchange derivatives		$ 1		$ (8)	$ (8)	$ (31)
Recurring Basis
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Assets at fair value		15,579			15,579		$ 14,054
Recurring Basis \| Level 2
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Assets at fair value		532			532		534
Foreign currency exchange derivatives \| Not Designated as Hedging Instrument \| Foreign currency purchases
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount		729			729		898
Foreign currency exchange derivatives \| Not Designated as Hedging Instrument \| Foreign currency sales
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount		1,101			1,101		839
Foreign currency exchange derivatives \| Not Designated as Hedging Instrument \| Recurring Basis
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Assets at fair value		7			7		9
Liabilities at fair value		12			12		7
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		7			7		9
Liabilities at fair value		$ 12			$ 12		$ 7
Reverse Treasury Lock \| Designated as Hedging Instrument \| Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount			$ 1,800
Losses on cash flow hedges			$ 15
Payments for reverse treasury lock agreements	$ 15