FAIR VALUE MEASUREMENTS - Cross-currency Swaps, Effect of Hedging Instruments on Financial Instruments (Details) - Currency Swap - Net Investment Hedging - Designated as Hedging Instrument $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Loss recognized in Other comprehensive loss	$ 22
Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Gain excluded from assessment of hedge effectiveness	$ 9