DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Details) € in Millions, ton in Millions, MWh in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 EUR (€) ton MWh	Sep. 30, 2025 USD ($) ton MWh	Dec. 31, 2024 EUR (€) ton MWh	Dec. 31, 2024 USD ($) ton MWh
Derivative [Line Items]
Assets						$ 76		$ 3
Liabilities						81		0
Derivative, collateral, right to reclaim cash						15
Other Current Assets
Derivative [Line Items]
Assets						45		$ 3
Other Noncurrent Assets
Derivative [Line Items]
Assets						31
Other Current Liabilities
Derivative [Line Items]
Liabilities						72
Other Noncurrent Liabilities
Derivative [Line Items]
Liabilities						$ 9
Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Reclassified from AOCI Into Income	$ (8)	$ 0	$ (15)	$ 0
Electricity contracts (MWh) | Cash Flow Hedging | Derivatives designated as hedging instruments
Derivative [Line Items]
Derivative, nonmonetary notional amount | MWh					1.9	1.9	0.3	0.3
Natural gas contracts (MWh) | Cash Flow Hedging | Derivatives designated as hedging instruments
Derivative [Line Items]
Derivative, nonmonetary notional amount | MWh					8.1	8.1	0.0	0.0
Carbon credit contracts (tons) | Cash Flow Hedging | Derivatives designated as hedging instruments
Derivative [Line Items]
Derivative, nonmonetary notional amount | ton					0.3	0.3	0.0	0.0
External debt | Net Investment Hedging
Derivative [Line Items]
Gain (Loss) Recognized in AOCI on Derivatives	(86)	0	(163)	0
External debt | Net Investment Hedging | Derivatives designated as hedging instruments
Derivative [Line Items]
Derivative, notional amount | €					€ 3,310		€ 0
Commodity contracts | Derivatives designated as hedging instruments
Derivative [Line Items]
Gain (Loss) Recognized in Income	25	2	38	(9)
Assets						$ 5		$ 0
Liabilities						46		0
Commodity contracts | Derivatives not designated as hedging instruments
Derivative [Line Items]
Assets						71		3
Liabilities						$ 35		$ 0
Commodity contracts | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in AOCI on Derivatives	(2)	0	(54)	0
Gain (Loss) Reclassified from AOCI Into Income	(8)	0	(14)	0
Commodity contracts | Cash Flow Hedging | Derivatives designated as hedging instruments
Derivative [Line Items]
Gain (Loss) Recognized in Income	(26)	0	(49)	0
Interest rate contracts | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Reclassified from AOCI Into Income	$ 0	$ 0	$ (1)	$ 0