Financial Instruments and Risk Management - General (Details) $ / shares in Units, item in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($) item approach $ / shares	Dec. 31, 2021 USD ($)
Financial Instruments and Risk Management
Aggregate fair value of derivative instruments with credit-risk-related contingent features that were in a net liability position	$ 44	$ 3
Collateral amount posted for derivative instruments with credit-risk-related contingent features that were in a net liability position	$ 0
Commodity
Financial Instruments and Risk Management
Number of methods through which entity manages commodity price risk in connection with market price fluctuations of aluminum ingot | approach	2
Notional amount of derivatives	$ 1,758
Commodity | Cash Flow Hedging
Financial Instruments and Risk Management
Period within which derivative will expire	2 years
Currency
Financial Instruments and Risk Management
Notional amount of derivatives	$ 2,710
Gain (loss) on derivatives included in AOCI, net of tax	7
Net gain (loss) expected to be recognized in net earnings within the next 12 months	$ 22
Currency | Cash Flow Hedging
Financial Instruments and Risk Management
Period within which derivative will expire	2 years
Interest Rate
Financial Instruments and Risk Management
Notional amount of derivatives	$ 788
Interest Rate | Cash Flow Hedging
Financial Instruments and Risk Management
Period within which derivative will expire	1 year
Equity contracts
Financial Instruments and Risk Management
Combined notional value, shares | item	2.5
Change in company's stock price (in dollars per share) | $ / shares	$ 1