SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - NARRATIVE (Details) $ / shares in Units, $ in Millions	1 Months Ended		12 Months Ended
	Aug. 31, 2024 USD ($) shares	Dec. 31, 2023 USD ($) shares	Dec. 31, 2024 USD ($) segment $ / shares shares	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($)	Sep. 30, 2024 shares	Jun. 30, 2024 shares	Mar. 31, 2024 shares
Summary of Significant Accounting Policies [Line Items]
Number of reportable segments | segment			3
Non-voting limited partner interest			2.00%
Noncontrolling interest		$ 99	$ 321	$ 99
Common stock, outstanding (in shares) | shares		879,463,103	938,457,983	879,463,103		938,174,218	905,559,959	886,719,730
Assets		$ 74,008	$ 85,445	$ 74,008
Net sales			27,413	28,325	$ 36,234
Trade receivables, net		3,195	3,526	3,195
Net capitalized costs attributable to unproved properties		10,200	10,200	10,200
Goodwill			$ 668
Minimum period of investigations and cleanup for CERCLA sites			10 years
Gain on non-monetary exchange transactions			$ 30	120
Alden Leeds | Alden Leeds
Summary of Significant Accounting Policies [Line Items]
Increase in environmental remediation liability			925
Land
Summary of Significant Accounting Policies [Line Items]
Impairment and related charges			334	180
Carbon Engineering, Ltd.
Summary of Significant Accounting Policies [Line Items]
Other intangible assets			$ 920
Goodwill		$ 668		668
Crownrock L.P.
Summary of Significant Accounting Policies [Line Items]
Issuance of shares upon approval (in shares) | shares		29,600,000
Low end of range
Summary of Significant Accounting Policies [Line Items]
Amortization period (in years)			9 years
Low end of range | Chemical
Summary of Significant Accounting Policies [Line Items]
The estimated useful lives of occidental's chemical assets			3 years
Low end of range | Midstream and marketing
Summary of Significant Accounting Policies [Line Items]
The estimated useful lives of occidental's chemical assets			3 years
High end of range
Summary of Significant Accounting Policies [Line Items]
Amortization period (in years)			25 years
High end of range | Chemical
Summary of Significant Accounting Policies [Line Items]
The estimated useful lives of occidental's chemical assets			50 years
High end of range | Midstream and marketing
Summary of Significant Accounting Policies [Line Items]
The estimated useful lives of occidental's chemical assets			40 years
Outside North America
Summary of Significant Accounting Policies [Line Items]
Assets			$ 7,700
Net sales			$ 4,300
BlackRock, Inc.
Summary of Significant Accounting Policies [Line Items]
Equity method investment commitments		$ 550		550
Berkshire Hathaway
Summary of Significant Accounting Policies [Line Items]
Common stock, outstanding (in shares) | shares			264,000,000
Outstanding warrants (in shares) | shares			83,900,000
Preferred stock, shares outstanding (in shares) | shares			8,500,000,000
Berkshire Hathaway | Common Stock
Summary of Significant Accounting Policies [Line Items]
Option indexed to issuer's equity, strike price (in dollars per share) | $ / shares			$ 59.62
VIE's
Summary of Significant Accounting Policies [Line Items]
Construction in progress			$ 773
WES
Summary of Significant Accounting Policies [Line Items]
Non-voting general partner interest			2.30%
WES
Summary of Significant Accounting Policies [Line Items]
Number of shares sold (in shares) | shares	19,500,000
Sale of stock, consideration received on transaction	$ 697
Gain on sale	$ 489
Limited partner interest			43.50%
Minority interest in new venture			46.00%
Black Butte Coal Company
Summary of Significant Accounting Policies [Line Items]
Impairment of equity method investment				$ 29