FINANCIAL INSTRUMENTS - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Gain (loss) recognized in other comprehensive income (loss)		$ (1)	$ (1)	$ (1)
U.S. dollar
Derivative [Line Items]
Derivative, notional amount	$ 10	$ 10	10
Cross-currency swaps | U.S. dollar | September 2020
Derivative [Line Items]
Derivative, notional amount	250		$ 250
Cross-currency swaps | U.S. dollar | Mar - 25
Derivative [Line Items]
Cash proceeds	23
Gain (loss) recognized in other comprehensive income (loss)	$ 21