Financial Instruments and Risk Management - General (Details) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($) approach $ / shares shares
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 contracts	$ 1,104
Net gain (loss) included in AOCI, after-tax	(2)
Net gain (loss) included in AOCI, after-tax, expected to be recognized in net earnings within the next 12 months	$ (2)
Commodity | Cash Flow Hedging
Financial Instruments and Risk Management
Longest duration of forecasted cash flow hedge transactions in years	2 years
Currency
Financial Instruments and Risk Management
Notional amount of contracts	$ 4,552
Net gain (loss) included in AOCI, after-tax	(3)
Net gain (loss) included in AOCI, after-tax, expected to be recognized in net earnings within the next 12 months	$ 9
Currency | Cash Flow Hedging
Financial Instruments and Risk Management
Longest duration of forecasted cash flow hedge transactions in years	2 years
Interest Rate
Financial Instruments and Risk Management
Notional amount of contracts	$ 600
Net gain (loss) included in AOCI, after-tax	11
Net gain (loss) included in AOCI, after-tax, expected to be recognized in net earnings within the next 12 months	$ 11
Interest Rate | Cash Flow Hedging
Financial Instruments and Risk Management
Longest duration of forecasted cash flow hedge transactions in years	3 years
Equity contracts
Financial Instruments and Risk Management
Combined notional value (in shares) | shares	1.5
Change in company's stock price (in dollars per share) | $ / shares	$ 1