FINANCIAL INSTRUMENTS - Schedule of notional amounts of outstanding derivatives (Details) $ in Millions	Sep. 30, 2026 USD ($)
Less than 1 year \| USD \| Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 526
Less than 1 year \| USD \| Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	103
Less than 1 year \| CHF \| Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	62
Less than 1 year \| CHF \| Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	156
Less than 1 year \| CZK \| Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	3
Less than 1 year \| CZK \| Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	74
Less than 1 year \| Other currencies \| Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	7
Less than 1 year \| Other currencies \| Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	3
Less than 1 year \| Metal \| Derivatives that do not qualify for hedge accounting
Derivatives, Fair Value [Line Items]
Derivative, notional amount	414
Less than 1 year \| Natural gas \| Derivatives that do not qualify for hedge accounting
Derivatives, Fair Value [Line Items]
Derivative, notional amount	26
Over 1 year \| USD \| Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	403
Over 1 year \| USD \| Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	1
Over 1 year \| CHF \| Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	15
Over 1 year \| CHF \| Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	25
Over 1 year \| CZK \| Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	0
Over 1 year \| CZK \| Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	25
Over 1 year \| Other currencies \| Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	0
Over 1 year \| Other currencies \| Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	0
Over 1 year \| Metal \| Derivatives that do not qualify for hedge accounting
Derivatives, Fair Value [Line Items]
Derivative, notional amount	56
Over 1 year \| Natural gas \| Derivatives that do not qualify for hedge accounting
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 32

Less than 1 year | USD | Sold currencies