Financial Instruments - Derivative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Line Items]
Credit Derivative, Maximum Exposure, Undiscounted		$ 135
Cash and cash equivalents		5,000	$ 4,758
Restricted cash and cash equivalents		1,117	1,208
Restricted Cash and Cash Equivalents, Noncurrent		99	97
Total cash and cash equivalents and restricted cash and cash equivalents presented in the consolidated statements of cash flows		6,216	6,063	$ 6,539	$ 8,390
Export Proceeds, Percent	30.00%
Bank Time Deposits
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents		100	300
Designated for Smelter Development Projects
Cash and Cash Equivalents [Line Items]
Total cash and cash equivalents and restricted cash and cash equivalents presented in the consolidated statements of cash flows			200
Designated For Export Proceeds
Cash and Cash Equivalents [Line Items]
Restricted cash and cash equivalents		1,000	1,100
Assurance Bonds
Cash and Cash Equivalents [Line Items]
Restricted cash and cash equivalents		$ 100	$ 100