FINANCIAL INSTRUMENTS - Cross-currency swap contract (Details) € in Millions, ¥ in Millions, $ in Millions	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 JPY (¥)	Dec. 31, 2019 EUR (€)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 JPY (¥)
U.S. dollar
Derivative [Line Items]
Derivative, notional amount		$ 10			$ 10
Cross-currency swaps | U.S. dollar | Maturity Period July 2027
Derivative [Line Items]
Derivative, notional amount		1,100			0
Cross-currency swaps | U.S. dollar | Maturity Period March 2025
Derivative [Line Items]
Derivative, notional amount		500			500
Cross-currency swaps | U.S. dollar | Maturity Period Feb 2023
Derivative [Line Items]
Derivative, notional amount		$ 100			$ 100
Cross-currency swaps | Euro Member Countries, Euro | Maturity Period July 2027
Derivative [Line Items]
Derivative, notional amount | €	€ 976			€ 0
Cross-currency swaps | Euro Member Countries, Euro | Maturity Period March 2025
Derivative [Line Items]
Derivative, notional amount | €	€ 450			€ 450
Cross-currency swaps | Japanese yen | Maturity Period Feb 2023
Derivative [Line Items]
Derivative, notional amount | ¥			¥ 10,978			¥ 10,978