CONTINGENCIES (Environmental Obligations) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) state project	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2017 USD ($) site divisions
Site Contingency [Line Items]
Number of remediation projects | project	80
Number of US States with remediation projects | state	22
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of year	$ 1,740	$ 1,664	$ 1,584
Accretion Expense	119	110	104
Net additionsb	195	43	40
Spending	(115)	(77)	(64)
Balance at end of year	$ 1,939	$ 1,740	$ 1,664
Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration]	Current portion of environmental and asset retirement obligations	Current portion of environmental and asset retirement obligations	Current portion of environmental and asset retirement obligations
Environmental Loss Contingency, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Environmental and asset retirement obligations, less current portion	Environmental and asset retirement obligations, less current portion	Environmental and asset retirement obligations, less current portion
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Liabilities	Liabilities	Liabilities
Less current portion	$ (131)	$ (125)	$ (64)
Long-term portion	1,808	1,615	1,600
Estimated environmental cash payments (on an undiscounted and unescalated basis) [Abstract]
2024	131
2025	147
2026	139
2027	128
2028	108
Thereafter	3,900
Estimated environmental obligations on a discounted basis	1,800
Estimated environmental obligations on an undiscounted and unescalated	$ 4,500
Environmental Loss Contingency, Number of Uranium Sites on Tribal Lands | divisions				94
Remediation work related to Uranium mines, amount to be contributed by the U.S. Government				$ 335
Uranium mine remediation work, program term, in years				20 years
Number of site surveys being performed to mining claims | site				15,000
Active remediation projects, percent	50.00%
Settlements and revisions to cash flow estimates, net	$ 54	381	331
Minimum
Estimated environmental cash payments (on an undiscounted and unescalated basis) [Abstract]
Estimated environmental obligations on an undiscounted and unescalated	3,900
Maximum
Estimated environmental cash payments (on an undiscounted and unescalated basis) [Abstract]
Estimated environmental obligations on an undiscounted and unescalated	5,000
Pinal Creek, AZ; Newtown Creek, NY; Smelter Sites in Arizona, Indiana, Kansas, Missouri, New Jersey, Oklahoma, Pennsylvania; and Uranium Mining in Wester United States
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at end of year	1,600
Newtown Creek
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at end of year	423
Estimated environmental cash payments (on an undiscounted and unescalated basis) [Abstract]
Accrual for Environmental Loss Contingencies, Period Increase (Decrease)	64
Sixty Percent of Remediation Projects
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at end of year	20
Pinal Creek, AZ
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at end of year	518
Estimated environmental cash payments (on an undiscounted and unescalated basis) [Abstract]
Accrual for Environmental Loss Contingencies, Period Increase (Decrease)	61
Historical Smelter Sites
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at end of year	262
Uranium Mining Sites
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at end of year	$ 444
Pt Freeport Indonesia Environmental And Reclamation Programs
Estimated environmental cash payments (on an undiscounted and unescalated basis) [Abstract]
Settlements and revisions to cash flow estimates, net		$ 131	$ 397