FAIR VALUE MEASUREMENT (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / bbl	Dec. 31, 2018 USD ($) $ / bbl	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) $ / bbl
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Other current assets	$ 655	$ 422
Other assets	1,885	2,172
Other assets	109	93	$ 72
Derivative Liability, Fair Value, Gross Liability	21	48
Derivatives:
Derivative Asset	74	16
Derivatives: [Abstract]
Derivative Liability	21	41
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	27	25
Assets [Abstract]
Trust Assets Fair Value Disclosure	59	55
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	4	4
Assets [Abstract]
Trust Assets Fair Value Disclosure	3	5
Derivatives:
Derivative Asset	5	0
Contingent receivable	0	0
Derivatives: [Abstract]
Derivative Liability	0	7
Long-term debt, including current portion	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	0	0
Assets [Abstract]
Trust Assets Fair Value Disclosure	134	121
Derivatives:
Derivative Asset	80	96
Contingent receivable	0	0
Derivatives: [Abstract]
Derivative Liability	21	41
Long-term debt, including current portion	10,239	10,238
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	0	0
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Derivatives:
Derivative Asset	0	0
Contingent receivable	108	127
Derivatives: [Abstract]
Derivative Liability	0	0
Long-term debt, including current portion	0	0
Carrying Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	31	29
Assets [Abstract]
Trust Assets Fair Value Disclosure	196	181
Derivatives:
Derivative Asset	85	96
Contingent receivable	122	143
Derivatives: [Abstract]
Derivative Liability	21	48
Long-term debt, including current portion	9,826	11,141
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	31	29
Assets [Abstract]
Trust Assets Fair Value Disclosure	196	181
Derivatives:
Derivative Asset	85	96
Contingent receivable	108	127
Derivatives: [Abstract]
Derivative Liability	21	48
Long-term debt, including current portion	10,239	10,238
Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Liability, Fair Value, Gross Liability	20	39
Derivatives:
Derivative Asset	68	16
Derivatives: [Abstract]
Derivative Liability	20	32
Embedded Derivative Financial Instruments [Member] | Level 1
Derivatives:
Derivative Asset	0	0
Derivatives: [Abstract]
Derivative Liability	0	0
Embedded Derivative Financial Instruments [Member] | Level 2
Derivatives:
Derivative Asset	68	23
Derivatives: [Abstract]
Derivative Liability	20	39
Embedded Derivative Financial Instruments [Member] | Level 3
Derivatives:
Derivative Asset	0	0
Derivatives: [Abstract]
Derivative Liability	0	0
Embedded Derivative Financial Instruments [Member] | Carrying Amount, Fair Value Disclosure [Member]
Derivatives:
Derivative Asset	68	23
Derivatives: [Abstract]
Derivative Liability	20	39
Embedded Derivative Financial Instruments [Member] | Estimate of Fair Value Measurement [Member]
Derivatives:
Derivative Asset	68	23
Derivatives: [Abstract]
Derivative Liability	20	39
Commodity Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Liability, Fair Value, Gross Liability	1	9
Derivatives:
Derivative Asset	6	0
Derivatives: [Abstract]
Derivative Liability	1	9
Commodity Contract [Member] | Level 1
Derivatives: [Abstract]
Derivative Liability	0	7
Commodity Contract [Member] | Level 2
Derivatives: [Abstract]
Derivative Liability	1	2
Commodity Contract [Member] | Level 3
Derivatives: [Abstract]
Derivative Liability	0	0
Commodity Contract [Member] | Carrying Amount, Fair Value Disclosure [Member]
Derivatives: [Abstract]
Derivative Liability	1	9
Commodity Contract [Member] | Estimate of Fair Value Measurement [Member]
Derivatives: [Abstract]
Derivative Liability	1	9
Future [Member] | Level 1
Derivatives:
Derivative Asset	5
Future [Member] | Level 2
Derivatives:
Derivative Asset	1
Future [Member] | Level 3
Derivatives:
Derivative Asset	0
Future [Member] | Carrying Amount, Fair Value Disclosure [Member]
Derivatives:
Derivative Asset	6
Future [Member] | Estimate of Fair Value Measurement [Member]
Derivatives:
Derivative Asset	6
Africa and onshore California [Member] | Commodity Contract [Member] | Level 1
Derivatives:
Derivative Asset	0	0
Africa and onshore California [Member] | Commodity Contract [Member] | Level 2
Derivatives:
Derivative Asset	11	73
Africa and onshore California [Member] | Commodity Contract [Member] | Level 3
Derivatives:
Derivative Asset	0	0
Africa and onshore California [Member] | Commodity Contract [Member] | Carrying Amount, Fair Value Disclosure [Member]
Derivatives:
Derivative Asset	11	73
Africa and onshore California [Member] | Commodity Contract [Member] | Estimate of Fair Value Measurement [Member]
Derivatives:
Derivative Asset	11	73
U.S. core fixed income fund [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	27	25
Assets [Abstract]
Trust Assets Fair Value Disclosure	59	55
U.S. core fixed income fund [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	0	0
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
U.S. core fixed income fund [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	0	0
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
U.S. core fixed income fund [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	0	0
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
U.S. core fixed income fund [Member] | Carrying Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	27	25
Assets [Abstract]
Trust Assets Fair Value Disclosure	59	55
U.S. core fixed income fund [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	27	25
Assets [Abstract]
Trust Assets Fair Value Disclosure	59	55
Money market funds [Member] | Level 1
Assets [Abstract]
Trust Assets Fair Value Disclosure	3	5
Money market funds [Member] | Level 2
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Money market funds [Member] | Level 3
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Money market funds [Member] | Carrying Amount, Fair Value Disclosure [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	3	5
Money market funds [Member] | Estimate of Fair Value Measurement [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	3	5
Equity securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	4	4
Equity securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	0	0
Equity securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	0	0
Equity securities | Carrying Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	4	4
Equity securities | Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Marketable Securities	4	4
Government bonds | Level 1
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Government bonds | Level 2
Assets [Abstract]
Trust Assets Fair Value Disclosure	36	36
Government bonds | Level 3
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Government bonds | Carrying Amount, Fair Value Disclosure [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	36	36
Government bonds | Estimate of Fair Value Measurement [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	36	36
Government mortgage-backed securities [Member] | Level 1
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Government mortgage-backed securities [Member] | Level 2
Assets [Abstract]
Trust Assets Fair Value Disclosure	43	38
Government mortgage-backed securities [Member] | Level 3
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Government mortgage-backed securities [Member] | Carrying Amount, Fair Value Disclosure [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	43	38
Government mortgage-backed securities [Member] | Estimate of Fair Value Measurement [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	43	38
Corporate bonds [Member] | Level 1
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Corporate bonds [Member] | Level 2
Assets [Abstract]
Trust Assets Fair Value Disclosure	33	28
Corporate bonds [Member] | Level 3
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Corporate bonds [Member] | Carrying Amount, Fair Value Disclosure [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	33	28
Corporate bonds [Member] | Estimate of Fair Value Measurement [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	33	28
Asset-backed securities [Member] | Level 1
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Asset-backed securities [Member] | Level 2
Assets [Abstract]
Trust Assets Fair Value Disclosure	14	11
Asset-backed securities [Member] | Level 3
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Asset-backed securities [Member] | Carrying Amount, Fair Value Disclosure [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	14	11
Asset-backed securities [Member] | Estimate of Fair Value Measurement [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	14	11
Collateralized Mortgage Backed Securities [Member] | Level 1
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Collateralized Mortgage Backed Securities [Member] | Level 2
Assets [Abstract]
Trust Assets Fair Value Disclosure	7	7
Collateralized Mortgage Backed Securities [Member] | Level 3
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Collateralized Mortgage Backed Securities [Member] | Carrying Amount, Fair Value Disclosure [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	7	7
Collateralized Mortgage Backed Securities [Member] | Estimate of Fair Value Measurement [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	7	7
Municipal bonds [Member] | Level 1
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Municipal bonds [Member] | Level 2
Assets [Abstract]
Trust Assets Fair Value Disclosure	1	1
Municipal bonds [Member] | Level 3
Assets [Abstract]
Trust Assets Fair Value Disclosure	0	0
Municipal bonds [Member] | Carrying Amount, Fair Value Disclosure [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	1	1
Municipal bonds [Member] | Estimate of Fair Value Measurement [Member]
Assets [Abstract]
Trust Assets Fair Value Disclosure	1	1
Bank Time Deposits [Member] | Carrying Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Other current assets	100	109
Other assets	157	126
Derivatives Not Designated as Hedging Instruments | Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Derivative Liability, Fair Value, Gross Liability	20	39
Freeport-McMoRan Oil & Gas | Onshore California
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Other assets	11	16
Other assets	50	50
Derivatives:
Contingent receivable	50			$ 150
Derivatives: [Abstract]
Contingent consideration asset, per year				50
Freeport-McMoRan Oil & Gas | Deepwater Gulf of Mexico Interests
Fair Value, Assets and Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Other current assets	18	27
Other assets	$ 104	$ 116
Derivatives:
Contingent receivable				$ 150
Crude Oil | Freeport-McMoRan Oil & Gas | Onshore California
Derivatives: [Abstract]
Contingent consideration, reference threshold, price per barrel (in us dollars per pound) | $ / bbl	70	70		70