LONG-TERM DEBT - SCHEDULE (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, gross	$ 35,200
Long-term finance leases	316	$ 347
Current finance leases	42	51
Total debt and finance leases	36,185	38,588
Less current maturities of financing leases	(42)	(51)
Less current maturities of long-term debt	(398)	0
Long-term debt, net	35,745	38,537
Occidental
Debt Instrument [Line Items]
Long-term debt, gross	35,235	37,401
Unamortized discount, net	748	914
Debt issuance costs	(156)	(125)
Long-term finance leases	316	347
Long-term debt, net	$ 35,745	$ 38,537
4.850% senior notes due 2021 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.85%	4.85%
Long-term debt, gross	$ 147	$ 677
2.600% senior notes due 2021 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	2.60%	2.60%
Long-term debt, gross	$ 224	$ 1,500
4.100% senior note due 2021 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.10%	4.10%
Long-term debt, gross	$ 0	$ 1,249
Variable rate bonds due 2021 \| Variable rate bonds \| Occidental
Debt Instrument [Line Items]
Debt instrument, variable rate	1.193%	2.854%
Long-term debt, gross	$ 27	$ 500
Variable rate bonds due 2021, 3.151% \| Variable rate bonds \| Occidental
Debt Instrument [Line Items]
Debt instrument, variable rate	3.151%	3.151%
Long-term debt, gross	$ 0	$ 500
2-year variable rate Term Loan due 2021, 3.111% \| Secured Debt \| Occidental
Debt Instrument [Line Items]
Debt instrument, variable rate	3.111%	3.111%
Debt instrument, term	2 years	2 years
Long-term debt, gross	$ 0	$ 1,956
2.700% senior notes due 2022 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	2.70%	2.70%
Long-term debt, gross	$ 629	$ 2,000
3.125% senior notes due 2022 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	3.125%	3.125%
Long-term debt, gross	$ 276	$ 814
2.600% senior notes due 2022 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	2.60%	2.60%
Long-term debt, gross	$ 101	$ 400
Variable rate bonds due 2022 \| Variable rate bonds \| Occidental
Debt Instrument [Line Items]
Debt instrument, variable rate	1.73%	3.36%
Long-term debt, gross	$ 1,052	$ 1,500
2.700% senior notes due 2023 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	2.70%	2.70%
Long-term debt, gross	$ 927	$ 1,191
8.750% medium-term notes due 2023 \| Medium-term notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	8.75%	8.75%
Long-term debt, gross	$ 22	$ 22
2.900% senior notes due 2024 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	2.90%	2.90%
Long-term debt, gross	$ 3,000	$ 3,000
6.950% senior notes due 2024 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.95%	6.95%
Long-term debt, gross	$ 650	$ 650
3.450% senior notes due 2024 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	3.45%	3.45%
Long-term debt, gross	$ 248	$ 248
8.000% senior notes due 2025 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	8.00%	8.00%
Long-term debt, gross	$ 500	$ 0
5.875% senior notes due 2025 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	5.875%	5.875%
Long-term debt, gross	$ 900	$ 0
3.500% senior notes due 2025 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	3.50%	3.50%
Long-term debt, gross	$ 750	$ 750
5.500% senior notes due 2025 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	5.50%	5.50%
Long-term debt, gross	$ 750	$ 0
5.550% senior notes due 2026 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	5.55%	5.55%
Long-term debt, gross	$ 1,100	$ 1,100
3.200% senior notes due 2026 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	3.20%	3.20%
Long-term debt, gross	$ 1,000	$ 1,000
3.400% senior notes due 2026 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	3.40%	3.40%
Long-term debt, gross	$ 1,150	$ 1,150
7.500% debentures due 2026 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.50%	7.50%
Long-term debt, gross	$ 112	$ 112
8.500% senior notes due 2027 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	8.50%	8.50%
Long-term debt, gross	$ 500	$ 0
3.000% senior notes due 2027 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	3.00%	3.00%
Long-term debt, gross	$ 750	$ 750
7.125% debentures due 2027 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.125%	7.125%
Long-term debt, gross	$ 150	$ 150
7.000% debentures due 2027 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.00%	7.00%
Long-term debt, gross	$ 48	$ 48
6.625% debentures due 2028 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.625%	6.625%
Long-term debt, gross	$ 14	$ 14
7.150% debentures due 2028 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.15%	7.15%
Long-term debt, gross	$ 235	$ 235
7.200% senior debentures due 2028 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.20%	7.20%
Long-term debt, gross	$ 82	$ 82
6.375% senior notes due 2028 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.375%	6.375%
Long-term debt, gross	$ 600	$ 0
7.200% debentures due 2029 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.20%	7.20%
Long-term debt, gross	$ 135	$ 135
7.950% debentures due 2029 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.95%	7.95%
Long-term debt, gross	$ 116	$ 116
8.450% senior debentures due 2029 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	8.45%	8.45%
Long-term debt, gross	$ 116	$ 116
3.500% senior notes due 2029 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	3.50%	3.50%
Long-term debt, gross	$ 1,500	$ 1,500
Variable rate bonds due 2030 \| Variable rate bonds \| Occidental
Debt Instrument [Line Items]
Debt instrument, variable rate	4.21%	1.705%
Long-term debt, gross	$ 68	$ 68
8.875% senior notes due 2030 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	8.875%	8.875%
Long-term debt, gross	$ 1,000	$ 0
6.625% senior notes due 2030 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.625%	6.625%
Long-term debt, gross	$ 1,500	$ 0
6.125% senior notes due 2031 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.125%	6.125%
Long-term debt, gross	$ 1,250	$ 0
7.500% senior notes due 2031 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.50%	7.50%
Long-term debt, gross	$ 900	$ 900
7.875% senior notes due 2031 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.875%	7.875%
Long-term debt, gross	$ 500	$ 500
6.450% senior notes due 2036 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.45%	6.45%
Long-term debt, gross	$ 1,750	$ 1,750
Zero Coupon senior notes due 2036 \| Senior notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	5.24%
Zero Coupon senior notes due 2036 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Long-term debt, gross	$ 2,269	$ 2,271
6.500% note payable to WES due 2038 \| Note payable \| WES
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.50%	6.50%
Long-term debt, gross	$ 0	$ 260
4.300% senior notes due 2039 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.30%	4.30%
Long-term debt, gross	$ 750	$ 750
7.950% senior notes due 2039 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.95%	7.95%
Long-term debt, gross	$ 325	$ 325
6.200% senior notes due 2040 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.20%	6.20%
Long-term debt, gross	$ 750	$ 750
4.500% senior notes due 2044 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.50%	4.50%
Long-term debt, gross	$ 625	$ 625
4.625% senior notes due 2045 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.625%	4.625%
Long-term debt, gross	$ 750	$ 750
6.600% senior notes due 2046 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.60%	6.60%
Long-term debt, gross	$ 1,100	$ 1,100
4.400% senior notes due 2046 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.40%	4.40%
Long-term debt, gross	$ 1,200	$ 1,200
4.100% senior notes due 2047 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.10%	4.10%
Long-term debt, gross	$ 750	$ 750
4.200% senior notes due 2048 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.20%	4.20%
Long-term debt, gross	$ 1,000	$ 1,000
4.400% senior notes due 2049 \| Senior notes \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.40%	4.40%
Long-term debt, gross	$ 750	$ 750
7.730% debentures due 2096 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.73%	7.73%
Long-term debt, gross	$ 60	$ 60
7.500% debentures due 2096 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.50%	7.50%
Long-term debt, gross	$ 78	$ 78
7.250% debentures due 2096 \| Debentures \| Occidental
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.25%	7.25%
Long-term debt, gross	$ 49	$ 49

Finance Lease, Liability, Current Maturities

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- Definition

Long-term Debt, Current Maturities Excluding Finance Leases

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No definition available.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Amount, after accumulated amortization, of debt discount (premium).

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease, classified as current.

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Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.

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Amount of long-term debt and lease obligation, including portion classified as current.

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No definition available.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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