SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - NARRATIVE (Details) $ in Millions		3 Months Ended		12 Months Ended
	Aug. 08, 2019	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Oct. 31, 2021 USD ($)	Jan. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)
Summary of Significant Accounting Policies [Line Items]
Number of reportable segments | segment				3
Equity method investment amounts				$ 2,938	$ 3,250
Assets				75,036	80,064	$ 107,190
Net sales				25,959	17,130	19,192
Trade receivables, net				4,208	2,115
Net capitalized costs attributable to unproved properties				14,800	18,600
Impairment and related charges		$ 8,600				285
Accrued liabilities for accrued payroll, commissions and related expenses				677	461
Dividends payable				188	189
Derivative financial instruments, included in accrued liabilities - current				$ 200	1,100
Minimum period of investigations and cleanup for Comprehensive Environmental Response, Compensation and Liability Act National Priorities List sites				10 years
Oil and gas
Summary of Significant Accounting Policies [Line Items]
Net sales				$ 19,285	11,995	14,048
Impairment and related charges		6,400	$ 581
Low end of range | Chemical
Summary of Significant Accounting Policies [Line Items]
The estimated useful lives of Occidental's chemical assets				3 years
High end of range | Chemical
Summary of Significant Accounting Policies [Line Items]
The estimated useful lives of Occidental's chemical assets				50 years
Outside North America
Summary of Significant Accounting Policies [Line Items]
Assets				$ 7,700
Net sales				4,200
Proved and unproved non-core Permian | Oil and gas
Summary of Significant Accounting Policies [Line Items]
Impairment and related charges				282	7,000
Qatar ISSD
Summary of Significant Accounting Policies [Line Items]
Impairment and related charges						$ 39
Ghana Assets
Summary of Significant Accounting Policies [Line Items]
Impairment and related charges					2,200
Disposed of by sale | Mozambique LNG Assets
Summary of Significant Accounting Policies [Line Items]
Sale consideration									$ 4,200
Disposed of by sale | South Africa Assets
Summary of Significant Accounting Policies [Line Items]
Sale consideration								$ 100
Disposed of by sale | Ghana Operations
Summary of Significant Accounting Policies [Line Items]
Sale consideration							$ 750
Discontinued Operations, Held-for-sale | Ghana Operations
Summary of Significant Accounting Policies [Line Items]
Sale consideration							$ 750
Discontinued Operations, Held-for-sale | Ghana Assets
Summary of Significant Accounting Policies [Line Items]
Impairment and related charges		$ 2,200
WES
Summary of Significant Accounting Policies [Line Items]
Equity method investment amounts				2,000
Impairment and related charges			$ 1,200
Goodwill derecognized					$ 1,200
WES Operating | WES
Summary of Significant Accounting Policies [Line Items]
Limited partner interest	98.00%
WES
Summary of Significant Accounting Policies [Line Items]
Pro-rata interest in net assets				$ 362
Non-voting general partner interest				2.20%
Limited partner interest				49.70%
Non-voting limited partner interest				2.00%
Effective economic interest				51.80%