Occidental Petroleum Corporatio (OXY) 10-Q 5 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2018shares
Document and Entity Information
Entity Registrant Name	OCCIDENTAL PETROLEUM CORP /DE/
Entity Central Index Key	797,468
Current Fiscal Year End Date	--12-31
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding	755,025,938

CONSOLIDATED CONDENSED BALANCE

CONSOLIDATED CONDENSED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
CURRENT ASSETS
Cash and cash equivalents	$ 2,954	$ 1,672
Trade receivables, net	6,000	4,145
Inventories	1,009	1,246
Assets held for sale	0	474
Other current assets	1,149	733
Total current assets	11,112	8,270
INVESTMENTS IN UNCONSOLIDATED ENTITIES	1,568	1,515
PROPERTY, PLANT AND EQUIPMENT, net of accumulated depreciation, depletion and amortization of $41,825 at September 30, 2018, and $39,072 at December 31, 2017	31,155	31,174
LONG-TERM RECEIVABLES AND OTHER ASSETS, NET	1,122	1,067
TOTAL ASSETS	44,957	42,026
CURRENT LIABILITIES
Current maturities of long-term debt	116	500
Accounts payable	5,443	4,408
Accrued liabilities	2,813	2,492
Total current liabilities	8,372	7,400
LONG-TERM DEBT, NET	10,198	9,328
DEFERRED CREDITS AND OTHER LIABILITIES
Deferred domestic and foreign income taxes	1,162	581
Asset retirement obligations	1,249	1,241
Pension and postretirement obligations	828	1,005
Environmental remediation reserves	740	728
Other	915	1,171
Total deferred credits and other liabilities	4,894	4,726
STOCKHOLDERS' EQUITY
Common stock, at par value (894,874,771 shares at September 30, 2018 and 893,468,707 shares at December 31, 2017)	179	179
Treasury stock (140,886,833 shares at September 30, 2018, and 128,364,195 shares at December 31, 2017)	(10,162)	(9,168)
Additional paid-in capital	7,991	7,884
Retained earnings	23,635	21,935
Accumulated other comprehensive loss	(154)	(258)
Total equity attributable to common stock	21,489	20,572
Noncontrolling interest	4	0
Total stockholders’ equity	21,493	20,572
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 44,957	$ 42,026

CONSOLIDATED CONDENSED BALANC_2

CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accumulated depreciation, depletion and amortization	$ 41,825	$ 39,072
Common stock, outstanding (in shares)	894,874,771	893,468,707
Treasury stock (in shares)	140,886,833	128,364,195

CONSOLIDATED CONDENSED STATEMEN

CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
REVENUES AND OTHER INCOME
Net sales	$ 5,216	$ 2,999	$ 13,062	$ 9,016
Interest, dividends and other income	34	20	101	72
Gain on sale of assets, net	926	86	969	598
TOTAL REVENUES AND OTHER INCOME	6,176	3,105	14,132	9,686
COSTS AND OTHER DEDUCTIONS
Cost of sales	1,786	1,357	4,614	4,269
Selling, general and administrative and other operating expenses	431	352	1,140	976
Taxes other than on income	110	76	333	221
Depreciation, depletion and amortization	1,023	995	2,891	2,926
Asset impairments and related items	214	11	256	24
Exploration expense	24	8	60	27
Interest and debt expense, net	96	91	290	258
TOTAL COSTS AND OTHER DEDUCTIONS	3,684	2,890	9,584	8,701
Income before income taxes and other items	2,492	215	4,548	985
Provision for domestic and foreign income taxes	(710)	(85)	(1,351)	(448)
Income from equity investments	87	60	228	277
NET INCOME	$ 1,869	$ 190	$ 3,425	$ 814
BASIC EARNINGS PER COMMON SHARE (in dollars per share)	$ 2.44	$ 0.25	$ 4.46	$ 1.06
DILUTED EARNINGS PER COMMON SHARE (in dollars per share)	2.44	0.25	4.45	1.06
DIVIDENDS PER COMMON SHARE (in dollars per share)	$ 0.78	$ 0.77	$ 2.32	$ 2.29

CONSOLIDATED CONDENSED STATEM_2

CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 1,869	$ 190	$ 3,425	$ 814
Other comprehensive income (loss) items:
Foreign currency translation gains		0	2	0	3
Unrealized gains (losses) on derivatives	[1]	(1)	8	(5)	14
Pension and postretirement gains (losses)	[2]	144	4	153	12
Reclassification of realized (gains) losses on derivatives	[3]	10	0	13	(1)
Other comprehensive income, net of tax		153	14	161	28
Comprehensive income		$ 2,022	$ 204	$ 3,586	$ 842
[1]	Net of tax of zero and $(5) for the three months ended September 30, 2018, and 2017, respectively, and $1 and $(8) for the nine months ended September 30, 2018, and 2017, respectively.
[2]	Net of tax of $(40) and $(3) for the three months ended September 30, 2018, and 2017, respectively, and $(43) and $(7) for the nine months ended September 30, 2018, and 2017, respectively. The three and nine months ended September 30, 2018 include $139 ($178 pre-tax) of other comprehensive income related to a postretirement benefit plan design change. Please refer to Note 9.
[3]	Net of tax of $(3) and zero for the three months ended September 30, 2018, and 2017, respectively, and $(4) and $1 for the nine months ended September 30, 2018, and 2017, respectively.

CONSOLIDATED CONDENSED STATEM_3

CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) on derivatives, tax	$ 0	$ (5)	$ 1	$ (8)
Pension and postretirement gains, tax	(40)	(3)	(43)	(7)
Other comprehensive income related to postretirement benefit plan design change	139		0
Other comprehensive income related to postretirement benefit plan design change, pre-tax	178		0
Reclassification to income of realized (gains) losses on derivatives, tax	$ (3)	$ 0	$ (4)	$ 1

CONSOLIDATED CONDENSED STATEM_4

CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOW FROM OPERATING ACTIVITIES
Net income	$ 3,425	$ 814
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization of assets	2,891	2,926
Deferred income tax provision (benefit)	550	(111)
Other noncash charges to income	74	170
Gain on sale of assets, net	(969)	(598)
Asset impairments and related items	256	24
Undistributed earnings from affiliates	(16)	(70)
Dry hole expenses	27	8
Changes in operating assets and liabilities, net	(1,069)	(445)
Other operating, net	0	722
Net cash provided by operating activities	5,169	3,440
CASH FLOW FROM INVESTING ACTIVITIES
Capital expenditures	(3,638)	(2,439)
Change in capital accrual	7	20
Payments for purchases of assets and businesses	(726)	(1,060)
Sales of assets, net	2,745	1,293
Equity investments and other, net	(88)	60
Net cash used by investing activities	(1,700)	(2,126)
CASH FLOW FROM FINANCING ACTIVITIES
Proceeds from long-term debt, net	978	0
Payments of long-term debt	(500)	0
Proceeds from issuance of common stock	17	25
Purchases of treasury stock	(908)	(12)
Cash dividends paid	(1,780)	(1,754)
Contributions from noncontrolling interest	4	0
Other financing, net	2	0
Net cash used by financing activities	(2,187)	(1,741)
Increase (decrease) in cash and cash equivalents	1,282	(427)
Cash and cash equivalents — beginning of period	1,672	2,233
Cash and cash equivalents — end of period	$ 2,954	$ 1,806

General

General	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General In these unaudited, consolidated, condensed financial statements, "Occidental" means Occidental Petroleum Corporation, a Delaware corporation (OPC), or OPC and one or more entities in which it owns a controlling interest (subsidiaries). Occidental has made its disclosures in accordance with United States generally accepted accounting principles (GAAP) as they apply to interim reporting, and condensed or omitted, as permitted by the Securities and Exchange Commission’s rules and regulations, certain information and disclosures normally included in consolidated financial statements and the notes. These unaudited consolidated condensed financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto in Occidental’s Annual Report on Form 10-K for the year ended December 31, 2017 . In the opinion of Occidental’s management, the accompanying unaudited consolidated condensed financial statements contain all adjustments (consisting of normal recurring adjustments) necessary to fairly present Occidental’s consolidated financial position as of September 30, 2018 , and the consolidated statements of operations, comprehensive income for the three and nine months ended September 30, 2018 , and 2017 , and cash flows for the nine months ended September 30, 2018, and 2017. Certain data in the financial statements and notes for prior periods have been reclassified to conform to the current presentation. The income and cash flows for the periods ended September 30, 2018 , and 2017 , are not necessarily indicative of the income or cash flows to be expected for the full year.

Asset Acquisitions, Disposition

Asset Acquisitions, Dispositions and Other	9 Months Ended
	Sep. 30, 2018
Asset Acquisitions, Dispositions and Other
Asset Acquisitions, Dispositions and Other	Asset Acquisitions, Dispositions and Other In September 2018, Occidental divested non-core domestic midstream assets for total consideration of $2.6 billion , of which approximately $2.4 billion was received at closing, resulting in a pre-tax net gain of $902 million . These assets include the Centurion common carrier oil pipeline and storage system, Southeast New Mexico oil gathering system, and Ingleside Crude Terminal. Following the transaction, Occidental retained its long-term flow assurance, pipeline takeaway and export capacity through its retained marketing business. In July 2018, Occidental acquired the previously leased power and steam cogeneration facility in Louisiana for $443 million , with one payment of approximately $60 million remaining to be settled in the fourth quarter of 2018. In March 2018, Occidental divested non-core midstream assets for approximately $150 million , resulting in a pre-tax gain of $43 million . In March 2018, Occidental issued $1.0 billion of 4.2 -percent senior notes due 2048. Occidental received net proceeds of approximately $985 million . Interest on the notes will be payable semi-annually in arrears in March and September of each year, beginning on September 15, 2018. The proceeds were used to refinance the repayment of the $500 million aggregate principal amount of Occidental's 1.5 -percent senior notes due in February 2018, with the remainder to be used for general corporate purposes. In January 2018, Occidental entered into a new five -year, $3.0 billion revolving credit facility (2018 Credit Facility), replacing the previous credit facility that was scheduled to expire in August 2019. The 2018 Credit Facility has similar terms to the previous credit facility and does not contain material adverse change clauses or debt ratings triggers that could restrict Occidental's ability to borrow under the facility.

Accounting and Disclosure Chang

Accounting and Disclosure Changes	9 Months Ended
	Sep. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Accounting and Disclosure Changes	Accounting and Disclosure Changes In February 2018, the Financial Accounting Standards Board (FASB) released standards that allow the reclassification from accumulated other comprehensive income to retained earnings of stranded tax effects resulting from changes to U.S. federal tax law from the 2017 Tax Cuts and Jobs Act enacted in December 2017. Occidental early adopted this standard in the first quarter of 2018, resulting in the reclassification of $58 million in stranded tax effects from accumulated other comprehensive income to retained earnings. In the first quarter of 2018, Occidental adopted the new revenue recognition standard Topic 606 - Revenue from Contracts with Customers and related updates (ASC 606). The new standard requires more detailed disclosures related to the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Occidental adopted the standard using the modified retrospective method. The cumulative-effect adjustment to retained earnings upon adoption was not material. See Note 4 Revenue Recognition . In March 2017, FASB issued guidance related to presentation of net periodic pension cost and net periodic postretirement benefit cost. The rules became effective in the first quarter of 2018. These rules did not have a material impact to Occidental's financial statements upon adoption. In January 2017, FASB issued new guidance clarifying the definition of a business under the topic Business Combinations. The rules became effective in the first quarter of 2018, and did not have a material impact to Occidental's financial statements upon adoption. In November 2016, FASB issued new guidance related to the cash flow classification and presentation of the changes in restricted cash on the statement of cash flows. The rules became effective in the first quarter of 2018 and must be applied retrospectively. Occidental did not have restricted cash as of September 30, 2018, or December 31, 2017. In August 2016, FASB issued new guidance related to the classification of certain cash receipts and payments on the statement of cash flows. The rules were adopted for the first quarter of 2018 and resulted in the retrospective reclassification of $135 million of cash receipts from operating cash flows to investing cash flows for the nine months ended September 30, 2017, within the Statement of Cash Flows. In February 2016, FASB issued rules which require Occidental to recognize most leases, including operating leases, on the balance sheet. The new rules require lessees to recognize a right-of-use asset and lease liability for all leases with lease terms of more than 12 months. The lease liability represents the discounted obligation to make future minimum lease payments. The corresponding right-of-use asset includes the discounted obligation in addition to any upfront payment or cost incurred during contract execution of the lease. Recognition, measurement and presentation of expenses and cash flows arising from a lease will depend on classification as a finance or operating lease. Occidental is the lessee under various agreements for real estate, equipment, plants and facilities, aircraft and information technology hardware that are currently accounted for as operating leases. As a result, these new rules will increase reported assets and liabilities. Occidental will not be an early adopter of this standard. Occidental will apply the revised lease rules for its interim and annual reporting periods starting January 1, 2019, using a modified retrospective approach, including several optional practical expedients related to leases that commenced before the effective date. Occidental is currently evaluating the effect of these rules on its financial statements, training employees, working with third-party consultants and has developed an internal interim software solution for the identification, documentation, tracking and accounting of leases as a means of an adoption plan based on Occidental's population of leases under the revised definition of leases. Occidental is currently in the test phase and continues to evaluate existing and new lease contracts for compliance, including performing various procedures to assess completeness in population and evaluating right-of-way contract structures under the new guidance to determine future impacts from adoption. The quantitative impacts of the new standard are dependent on the leases in force at the time of adoption. As a result, the evaluation of the effect of the new standard is ongoing.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition On January 1, 2018, Occidental adopted ASC 606 using the modified retrospective method. Results for reporting periods beginning after January 1, 2018, are presented under ASC 606, while prior period amounts have not been adjusted. There was no impact of adopting ASC 606 to the opening balance of retained earnings. There was no impact to the timing or amount of revenue recognized in the nine months ended September 30, 2018, as a result of the adoption of ASC 606. Revenue from customers is recognized when obligations under the terms of a contract with our customer are satisfied; this generally occurs with the delivery of oil, gas, natural gas liquids ("NGL"), chemicals or services such as transportation. Revenue from customers is measured as the amount of consideration Occidental expects to receive in exchange for the delivery of goods or services. Contracts may last from one month to one year or more, and may have renewal terms that extend indefinitely at the option of either party. Price is typically based on market indexes. Volumes fluctuate due to production and, in certain cases, customer demand and transportation availability. Occidental records revenue net of certain taxes, such as sales taxes, that are assessed by governmental authorities on Occidental's customers. Occidental has elected a practical expedient under ASC 606 and will not disclose revenue recognizable in future periods for unsatisfied performance obligations because the consideration related to those performance obligations is based on volume or market prices, which are variable. Occidental does not incur significant costs to obtain contracts. Incidental items that are immaterial in the context of the contract are recognized as expense. Sales of hydrocarbons and chemicals to customers are invoiced and settled on a monthly basis. Occidental is not usually subject to obligations for warranties, returns or refunds except in the case of customer incentive payments as discussed for the chemical segment below. Occidental does not typically receive payment in advance of satisfying its obligations under the terms of its sales contracts with customers; therefore, liabilities related to such payment are immaterial to Occidental. As of September 30, 2018, trade receivables, net, of $6.0 billion , represent rights to payment for which Occidental has satisfied its obligations under a contract and its right to payment is conditioned only on the passage of time. Oil and Gas Segment Revenue from oil and gas production is recognized when it is delivered and control passes to the customer. Revenues from the production of oil and gas properties in which Occidental has an interest with other producers are recognized on the basis of Occidental’s net revenue interest. Chemical Segment Revenue from chemical product sales is recognized when control passes to the customer. Certain incentive programs may provide for payments or credits to be made to customers based on the volume of product purchased over a defined period. Customer incentives are estimated and recorded as a reduction to revenue ratably over the contract period. Such estimates are evaluated and revised as warranted. Revenue from exchange contracts is excluded from revenue from customers. Midstream and Marketing Segment Revenue from pipeline and gas processing is recognized upon the completion of the transportation or processing service. Revenue from power sales is recognized upon delivery. Net marketing margin is included in net sales, but excluded from revenue from customers. Net marketing margin is recognized upon completion of contract terms that are a prerequisite to payment and upon title transfer for physical deliveries. Unless normal sales treatment has been elected, net marketing margin is classified as a derivative, reported on a net basis, recorded at fair value and changes in fair value are reflected in net sales. The following table shows a reconciliation of revenue from customers to total net sales (in millions): Three Months Ended September 30, 2018 Nine months Ended September 30, 2018 Revenue from customers $ 4,257 $ 11,813 All other revenues (a) 959 1,249 Total net sales $ 5,216 $ 13,062 (a) Includes net marketing margin and chemical exchange contracts. The following table presents Occidental's revenue from customers by segment, product and geographical area. Because the oil and gas segment typically sells its hydrocarbons at the lease or concession area, oil, gas and NGL are assumed to be sold in the area where they are produced. Chemical and midstream revenues are shown by area based on the location of the sale (in millions): For the three months ended September 30, 2018 Revenue by Product United States Middle East Latin America Other International Total Oil and Gas Segment Oil $ 1,326 $ 1,016 $ 197 $ — $ 2,539 NGL 139 77 — — 216 Gas 47 80 5 — 132 Other 3 — (1 ) — 2 Segment Total $ 1,515 $ 1,173 $ 201 $ — $ 2,889 Chemical Segment $ 1,112 $ — $ 51 $ 21 $ 1,184 Midstream Segment Marketing and Trading $ 3 $ — $ — $ — $ 3 Gas Processing 148 108 — — 256 Pipelines 115 — — — 115 Power and Other 35 — — — 35 Segment Total $ 301 $ 108 $ — $ — $ 409 Intersegment Eliminations $ (225 ) $ — $ — $ — $ (225 ) Consolidated $ 2,703 $ 1,281 $ 252 $ 21 $ 4,257 For the nine months ended September 30, 2018 Revenue by Product United States Middle East Latin America Other International Total Oil and Gas Segment Oil $ 3,907 $ 2,507 $ 547 $ — $ 6,961 NGL 339 192 — — 531 Gas 141 218 12 — 371 Other 10 1 — — 11 Segment Total $ 4,397 $ 2,918 $ 559 $ — $ 7,874 Chemical Segment $ 3,294 $ — $ 154 $ 59 $ 3,507 Midstream Segment Marketing and Trading $ 11 $ — $ — $ — $ 11 Gas Processing 416 308 — — 724 Pipelines 310 — — — 310 Power and Other 73 — — — 73 Segment Total $ 810 $ 308 $ — $ — $ 1,118 Intersegment Eliminations $ (686 ) $ — $ — $ — $ (686 ) Consolidated $ 7,815 $ 3,226 $ 713 $ 59 $ 11,813

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 30, 2018
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Occidental paid foreign and domestic state income taxes of $ 838 million and $ 553 million during the nine months ended September 30, 2018 , and 2017 , respectively. Occidental received domestic tax refunds of $ 2 million and $ 756 million during the nine months ended September 30, 2018, and 2017, respectively. Interest paid totaled $ 298 million and $ 266 million during the nine months ended September 30, 2018 , and 2017 , respectively.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories Finished goods primarily represents crude oil, caustic soda and vinyl products. Inventories as of September 30, 2018 , and December 31, 2017 , consisted of the following (in millions): 2018 2017 Raw materials $ 69 $ 66 Materials and supplies 434 447 Finished goods 549 776 1,052 1,289 Revaluation to LIFO (43 ) (43 ) Total $ 1,009 $ 1,246

Environmental Liabilities and E

Environmental Liabilities and Expenditures	9 Months Ended
	Sep. 30, 2018
Environmental Remediation Obligations [Abstract]
Environmental Liabilities and Expenditures	Environmental Liabilities and Expenditures Occidental’s operations are subject to stringent federal, state, local and foreign laws and regulations related to improving or maintaining environmental quality. The laws that require or address environmental remediation, including the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and similar federal, state, local and foreign laws, may apply retroactively and regardless of fault, the legality of the original activities or the current ownership or control of sites. OPC or certain of its subsidiaries participate in or actively monitor a range of remedial activities and government or private proceedings under these laws with respect to alleged past practices at operating, closed and third-party sites. Remedial activities may include one or more of the following: investigation involving sampling, modeling, risk assessment or monitoring; cleanup measures including removal, treatment or disposal of hazardous substances; or operation and maintenance of remedial systems. These environmental proceedings seek funding or performance of remediation and, in some cases, compensation for alleged property damage, punitive damages, civil penalties, injunctive relief and government oversight costs. As of September 30, 2018, Occidental participated in or monitored remedial activities or proceedings at 146 sites. The following table presents Occidental’s current and non-current environmental remediation reserves as of September 30, 2018, which were included in current liabilities ($ 136 million ) and deferred credits and other liabilities - environmental remediation reserves ($ 740 million ). The reserves are grouped as environmental remediation sites listed or proposed for listing by the United States Environmental Protection Agency on the CERCLA National Priorities List (NPL sites) and three categories of non-NPL sites — third-party sites, Occidental-operated sites and closed or non-operated Occidental sites. Number of Sites Reserve Balance NPL sites 34 $ 453 Third-party sites 69 172 Occidental-operated sites 14 114 Closed or non-operated Occidental sites 29 137 Total 146 $ 876 As of September 30, 2018, Occidental’s environmental reserves exceeded $10 million each at 16 of the 146 sites described above, and 90 of the sites each had reserves of $1 million or less. Based on current estimates, Occidental expects to expend funds corresponding to approximately 50 percent of the environmental reserves at the sites described above over the next three to four years and the balance at these sites over the subsequent 10 or more years. Occidental believes its estimable amount of reasonably possible additional losses beyond those liabilities recorded for environmental remediation at these sites could range up to $ 1.1 billion . The status of Occidental's involvement with the sites and related significant assumptions, including those sites indemnified by Maxus Energy Corporation (Maxus), has not changed materially since December 31, 2017. Maxus Environmental Sites When Occidental acquired Diamond Shamrock Chemicals Company (DSCC) in 1986, Maxus, a subsidiary of YPF S.A. (YPF), agreed to indemnify Occidental for a number of environmental sites, including the Diamond Alkali Superfund Site (Site) along a portion of the Passaic River. On September 17, 2016, Maxus and several affiliated companies filed for Chapter 11 bankruptcy in Federal District Court in the State of Delaware. Prior to filing for bankruptcy, Maxus defended and indemnified Occidental in connection with clean-up and other costs associated with the sites subject to the indemnity, including the Site. In March 2016, the EPA issued a Record of Decision (ROD) specifying remedial actions required for the lower 8.3 miles of the Lower Passaic River. The ROD does not address any potential remedial action for the upper nine miles of the Lower Passaic River or Newark Bay. During the third quarter of 2016, and following Maxus’s bankruptcy filing, Occidental and the EPA entered into an Administrative Order on Consent (AOC) to complete the design of the proposed clean-up plan outlined in the ROD at an estimated cost of $165 million . The EPA announced that it will pursue similar agreements with other potentially responsible parties. Occidental has accrued a reserve relating to its estimated allocable share of the costs to perform the design and the remediation called for in the AOC and the ROD, as well as for certain other Maxus-indemnified sites. Occidental's accrued estimated environmental reserve does not consider any recoveries for indemnified costs. Occidental’s ultimate share of this liability may be higher or lower than the reserved amount, and is subject to final design plans and the resolution of Occidental's allocable share with other potentially responsible parties. Occidental continues to evaluate the costs to be incurred to comply with the AOC, the ROD and to perform remediation at other Maxus-indemnified sites in light of the Maxus bankruptcy and the share of ultimate liability of other potentially responsible parties. In June 2018, Occidental filed a complaint under CERCLA in Federal District Court in the State of New Jersey against numerous potentially responsible parties for reimbursement of amounts incurred or to be incurred to comply with the AOC, the ROD or to perform other remediation activities at the Site. In September 2017, the court overseeing the Maxus bankruptcy approved a Plan of Liquidation (Plan) to liquidate Maxus and create a trust to pursue claims against YPF, Repsol and others to satisfy claims by Occidental and other creditors for past and future cleanup and other costs. In July 2017, the court-approved Plan became final and the trust became effective. Among other responsibilities, the trust will pursue claims against YPF, Repsol and others and distribute assets to Maxus' creditors in accordance with the trust agreement and Plan. In June 2018, the trust filed its complaint against YPF and Repsol in Delaware bankruptcy court asserting claims based upon, among other things, fraudulent transfer and alter ego.

Lawsuits, Claims, Commitments a

Lawsuits, Claims, Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Lawsuits, Claims, Commitments and Contingencies	Lawsuits, Claims, Commitments and Contingencies Legal Matters Occidental or certain of its subsidiaries are involved, in the normal course of business, in lawsuits, claims and other legal proceedings that seek, among other things, compensation for alleged personal injury, breach of contract, property damage or other losses, punitive damages, civil penalties, or injunctive or declaratory relief. Occidental or certain of its subsidiaries also are involved in proceedings under CERCLA and similar federal, state, local and foreign environmental laws. These environmental proceedings seek funding or performance of remediation and, in some cases, compensation for alleged property damage, punitive damages, civil penalties and injunctive relief. Usually Occidental or such subsidiaries are among many companies in these environmental proceedings and have to date been successful in sharing response costs with other financially sound companies. Further, some lawsuits, claims and legal proceedings involve acquired or disposed assets with respect to which a third party or Occidental retains liability or indemnifies the other party for conditions that existed prior to the transaction. In 2016, Occidental received payments from the Republic of Ecuador of approximately $1.0 billion pursuant to a November 2015 arbitration award for Ecuador’s 2006 expropriation of Occidental's Participation Contract for Block 15. The awarded amount represented a recovery of 60 percent of the value of Block 15. In 2017, Andes Petroleum Ecuador Ltd. (Andes) filed a demand for arbitration, claiming it is entitled to a 40 percent share of the judgment amount obtained by Occidental. Occidental contends that Andes is not entitled to any of the amounts paid under the 2015 arbitration award because Occidental’s recovery was limited to Occidental’s own 60 percent economic interest in the block. Occidental intends to vigorously defend against this claim in arbitration. In accordance with applicable accounting guidance, Occidental accrues reserves for outstanding lawsuits, claims and proceedings when it is probable that a liability has been incurred and the liability can be reasonably estimated. In Note 7, Environmental Liabilities and Expenditures, Occidental has disclosed its reserve balances for environmental remediation matters that satisfy this criteria. Reserve balances for matters, other than environmental remediation, that satisfy this criteria as of September 30, 2018, and December 31, 2017, were not material to Occidental’s consolidated balance sheets. The ultimate outcome and impact of outstanding lawsuits, claims and proceedings on Occidental cannot be predicted. Management believes that the resolution of these matters will not, individually or in the aggregate, have a material adverse effect on Occidental's consolidated balance sheet. If unfavorable outcomes of these matters were to occur, future results of operations or cash flows for any particular quarterly or annual period could be materially adversely affected. Occidental’s estimates are based on information known about the legal matters and its experience in contesting, litigating and settling similar matters. Occidental reassesses the probability and estimability of contingent losses as new information becomes available. Tax Matters During the course of its operations, Occidental is subject to audit by tax authorities for varying periods in various federal, state, local and foreign tax jurisdictions. Although taxable years through 2012 for United States federal income tax purposes have been audited by the United States Internal Revenue Service (IRS) pursuant to its Compliance Assurance Program, subsequent taxable years are currently under review. Taxable years from 2002 through the current year remain subject to examination by foreign and state government tax authorities in certain jurisdictions. In certain of these jurisdictions, tax authorities are in various stages of auditing Occidental’s income taxes. During the course of tax audits, disputes have arisen and other disputes may arise as to facts and matters of law. Occidental believes that the resolution of outstanding tax matters would not have a material adverse effect on its consolidated financial position or results of operations. Indemnities to Third Parties Occidental, its subsidiaries, or both, have indemnified various parties against specified liabilities those parties might incur in the future in connection with purchases and other transactions that they have entered into with Occidental. These indemnities usually are contingent upon the other party incurring liabilities that reach specified thresholds. As of September 30, 2018, Occidental is not aware of circumstances that it believes would reasonably be expected to lead to indemnity claims that would result in payments materially in excess of reserves. Purchase Obligations and Commitments Occidental has entered into agreements providing for future payments to secure terminal and pipeline capacity, drilling rigs and services, electrical power, steam and certain chemical raw materials. Occidental has certain other commitments under contracts, guarantees and joint ventures, including purchase commitments for goods and services at market-related prices and certain other contingent liabilities. In the third quarter of 2018, Occidental secured approximately $2 billion of additional long-term commitments related to pipeline and terminal capacity that extend over the next ten years .

Retirement and Postretirement B

Retirement and Postretirement Benefit Plans	9 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
Retirement and Postretirement Benefit Plans	Retirement and Postretirement Benefit Plans The following tables set forth the components of the net periodic benefit costs for Occidental’s defined benefit plans for the three and nine months ended September 30, 2018 , and 2017 (in millions): Three months ended September 30 2018 2017 Net Periodic Benefit Costs Pension Benefit Postretirement Benefit Pension Benefit Postretirement Benefit Service cost $ — $ 5 $ 2 $ 5 Interest cost 4 8 4 9 Expected return on plan assets (7 ) — (6 ) — Recognized actuarial loss 2 2 2 3 Additional settlement cost 3 — — — Total $ 2 $ 15 $ 2 $ 17 Nine months ended September 30 2018 2017 Net Periodic Benefit Costs Pension Benefit Postretirement Benefit Pension Benefit Postretirement Benefit Service cost $ 4 $ 17 $ 6 $ 15 Interest cost 12 26 12 29 Expected return on plan assets (19 ) — (18 ) — Recognized actuarial loss 4 12 6 11 Additional settlement cost 3 — — — Total $ 4 $ 55 $ 6 $ 55 Occidental contributed approximately $ 2 million and $1 million in the three months ended September 30, 2018, and 2017, and approximately $ 4 million and $3 million in the nine months ended September 30, 2018, and 2017, to its defined benefit plans. During the third quarter of 2018, Occidental adopted a postretirement benefit plan design change, which replaced the previous self-insured benefit with a Medicare Advantage PPO plan for Medicare-eligible retirees. As a result of this change, the postretirement benefit obligation was remeasured as of August 31, 2018. The remeasurement resulted in a decrease to the benefit obligation of $178 million , with a corresponding offset to accumulated other comprehensive income.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Occidental has categorized its assets and liabilities that are measured at fair value in a three-level fair value hierarchy, based on the inputs to the valuation techniques: Level 1 — using quoted prices in active markets for the assets or liabilities; Level 2 — using observable inputs other than quoted prices for the assets or liabilities; and Level 3 — using unobservable inputs. Transfers between levels, if any, are recognized at the end of each reporting period. The following tables provide fair value measurement information for such assets and liabilities that are measured on a recurring basis as of September 30, 2018 , and December 31, 2017 (in millions): Fair Value Measurements at September 30, 2018: Embedded derivatives Level 1 Level 2 Level 3 Netting and Total Fair Liabilities: Accrued liabilities $ — $ 11 $ — $ — $ 11 Deferred credits and other liabilities - other $ — $ 53 $ — $ — $ 53 Fair Value Measurements at December 31, 2017: Embedded derivatives Level 1 Level 2 Level 3 Netting and Total Fair Liabilities: Accrued liabilities $ — $ 39 $ — $ — $ 39 Deferred credits and other liabilities - other $ — $ 147 $ — $ — $ 147 Fair Values — Nonrecurring During the three months ended September 30, 2018, Occidental recognized pre-tax impairment charges of $196 million on proved oil and gas properties and inventory as a result of Qatar Petroleum’s decision to take over operatorship and ownership of the Idd El-Shargi North Dome offshore field in Qatar following the contract expiration in October 2019. The fair value of the proved properties was measured based on the income approach, which incorporated a number of assumptions involving expectations of future cash flows. These assumptions included estimates of future product prices, which Occidental based on forward price curves, estimates of oil and gas reserves, estimates of future expected operating and capital costs and a risk-adjusted discount rate. These inputs are categorized as Level 3 in the fair value hierarchy. As the end of the contract period approaches, significant changes to estimated future cash flows could result in additional impairment charges. In addition, for the nine months ended September 30, 2018, Occidental recognized pre-tax impairment charges of $42 million related to non-core proved Permian acreage and an investment in gas processing facilities. During the year ended December 31, 2017, Occidental recognized pre-tax impairment charges of $397 million primarily related to held-for-sale, non-core, proved and unproved Permian acreage. Other Financial Instruments The carrying amounts of cash and cash equivalents and other on-balance-sheet financial instruments, other than long-term, fixed-rate debt, approximate fair value. The cost, if any, to terminate Occidental's off-balance-sheet financial instruments is not significant. Occidental estimates the fair value of fixed-rate debt based on the quoted market prices for those instruments or on quoted market yields for similarly rated debt instruments, taking into account such instruments’ maturities. The estimated fair value of Occidental’s debt as of September 30, 2018 , and December 31, 2017 , was $10.4 billion . The remaining principal payments, less the discount on long-term debt, aggregated approximately $10.4 billion and $9.9 billion as of September 30, 2018, and December 31, 2017, respectively.

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives Occidental uses a variety of derivative financial instruments and physical contracts, including those designated as cash flow hedges, to manage its exposure to commodity price fluctuations, transportation commitments and to fix margins on the future sale of stored volumes of oil and natural gas. Where Occidental buys product for its own consumption or sells its production to a defined customer, Occidental elects normal purchases and normal sales exclusions. Occidental usually applies cash flow hedge accounting treatment to derivative financial instruments to lock in margins on the forecast sales of its natural gas storage volumes, and at times for other strategies to lock in margins. Occidental also enters into derivative financial instruments for speculative or trading purposes; however, the results of any transactions are immaterial to the marketing portfolio. The financial instruments not designated as hedges will impact Occidental's earnings through mark-to-market until the offsetting future physical commodity is delivered. For GAAP purposes, any physical inventory is carried at lower of cost or market on the balance sheet. A substantial majority of Occidental's physical derivative contracts are index-based and carry no mark-to-market value in earnings. Net gains and losses associated with derivative instruments not designated as hedging instruments are recognized currently in net sales. Net gains and losses attributable to derivative instruments subject to hedge accounting reside in accumulated other comprehensive loss and are reclassified to earnings as the transactions to which the derivatives relate are recognized in earnings. Credit Risk The majority of Occidental's counterparty credit risk is related to the physical delivery of energy commodities to its customers and any potential inability to meet their settlement commitments. Occidental manages credit risk by selecting counterparties that it believes to be financially strong, by entering into netting arrangements with counterparties and by requiring collateral or other credit risk mitigants, as appropriate. Occidental actively evaluates the creditworthiness of its counterparties, assigns appropriate credit limits and monitors credit exposures against those assigned limits. Occidental also enters into future contracts through regulated exchanges with select clearinghouses and brokers, which are subject to minimal credit risk as a significant portion of these transactions settle on a daily margin basis. Certain of Occidental's over-the-counter derivative instruments contain credit-risk-contingent features, primarily tied to credit ratings for Occidental or its counterparties, which may affect the amount of collateral that each would need to post. Occidental believes that if it had received a one-notch reduction in its credit ratings, it would not have resulted in a material change in its collateral-posting requirements as of September 30, 2018, and December 31, 2017. Cash flow Hedges Occidental’s marketing operations store natural gas purchased from third parties at Occidental’s leased storage facilities. Derivative instruments are used to fix margins on the future sales of the stored volumes. As of September 30, 2018, Occidental had approximately 6 billion cubic feet (Bcf) of natural gas held in storage, and had cash flow hedges for the forecast sales, to be settled by physical delivery, of approximately 4 Bcf of stored natural gas. As of December 31, 2017, Occidental had approximately 7 Bcf of natural gas held in storage, and had cash flow hedges for the forecast sales, to be settled by physical delivery, of approximately 7 Bcf of stored natural gas. The amount of cash flow hedges, including the ineffective portion, was immaterial for the nine months ended September 30, 2018, and the year ended December 31, 2017. Derivatives Not Designated as Hedging Instruments Forward unrealized instruments that are derivatives not designated as hedging instruments are required to be recorded on the income statement and balance sheet at fair value. The fair value represents an unrealized gain or loss between executed sales prices and market prices at the end of the period. The fair value does not reflect the realized or cash value of the instrument. Substantially all of the fair value of Occidental's derivative instruments not designated as hedges are used to manage its exposure to commodity price fluctuations and settle within three months at a weighted average contract price of $69.98 and $2.67 for crude oil and natural gas, respectively, at September 30, 2018. The remaining fair value of derivative instruments not designated as hedges was immaterial. The weighted average contract price was $57.38 and $2.73 for crude oil and natural gas, respectively, at December 31, 2017. The following table summarizes the amounts reported in net sales related to the outstanding commodity derivatives not designated as hedging instruments as of September 30, 2018, and December 31, 2017. (in millions, except Long/(Short) volumes) 2018 2017 Unrealized gain (loss) on derivatives not designated as hedges Crude Oil Commodity Contracts $ (37 ) $ (47 ) Natural Gas Commodity Contracts $ (1 ) $ 1 Outstanding net volumes on derivatives not designated as hedges Crude Oil Commodity Contracts Volume (MMBL) 73 61 Natural Gas Commodity Contracts Volume (Bcf) (88 ) (47 ) Fair Value of Derivatives The following table presents the gross and net fair values of Occidental’s outstanding derivatives as of September 30, 2018 , and December 31, 2017 (in millions): As of September 30, 2018 (in millions) Fair Value Measurements Using Netting (b) Total Fair Value Balance Sheet Location Level 1 Level 2 Level 3 Assets: Derivatives not designated as hedging instruments (a) Other current assets 1,210 631 — (1,235 ) 606 Long-term receivables and other assets, net 101 4 — (101 ) 4 Liabilities: Cash flow hedges (a) Accrued liabilities — 1 — — 1 Derivatives not designated as hedging instruments (a) Accrued liabilities 1,252 627 — (1,235 ) 644 Deferred credits and other liabilities - other 101 4 — (101 ) 4 As of December 31, 2017 (in millions) Fair Value Measurements Using Netting (b) Total Fair Value Balance Sheet Location Level 1 Level 2 Level 3 Assets: Cash flow hedges (a) Other current assets — 3 — — 3 Derivatives not designated as hedging instruments (a) Other current assets 485 227 — (517 ) 195 Long-term receivables and other assets, net 1 2 — (1 ) 2 Liabilities: Derivatives not designated as hedging instruments (a) Accrued liabilities 535 222 — (517 ) 240 Deferred credits and other liabilities - other 1 3 — (1 ) 3 (a) Fair values are presented at gross amounts, including when the derivatives are subject to master netting arrangements and presented on a net basis in the consolidated condensed balance sheets. (b) These amounts do not include collateral. As of September 30, 2018, no collateral received has been netted against derivative assets and collateral paid of $ 64 million has been netted against derivative liabilities. As of December 31, 2017, no collateral received has been netted against derivative assets and collateral paid of $ 54 million has been netted against derivative liabilities. Select clearinghouse and brokers require Occidental to post an initial margin deposit. Collateral deposited by Occidental, mainly for initial margin, of $ 73 million and $ 53 million as of September 30, 2018 and December 31, 2017, respectively, has not been reflected in these derivative fair -value tables. This collateral is included in other current assets in the consolidated condensed balance sheets.

Industry Segments

Industry Segments	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Industry Segments	Industry Segments Occidental conducts its operations through three segments: (1) oil and gas; (2) chemical; and (3) midstream and marketing. The oil and gas segment explores for, develops and produces oil and condensate, NGL and natural gas. The chemical segment mainly manufactures and markets basic chemicals and vinyls. The midstream and marketing segment gathers, processes, transports, stores, purchases and markets oil, condensate, NGL, natural gas, carbon dioxide (CO 2 ) and power. It also trades around its assets, including transportation and storage capacity. Additionally, the midstream and marketing segment invests in entities that conduct similar activities. Results of industry segments generally exclude income taxes, interest income, interest expense, environmental remediation expenses, unallocated corporate expenses and discontinued operations, but include gains and losses from dispositions of segment and geographic-area assets and income from the segments' equity investments. Intersegment sales eliminate upon consolidation and are generally made at prices approximating those that the selling entity would be able to obtain in third-party transactions. The following tables present Occidental’s industry segments (in millions): Oil Midstream Corporate and and and Gas Chemical Marketing Eliminations Total Three months ended September 30, 2018 Net sales $ 2,889 $ 1,185 $ 1,367 $ (225 ) $ 5,216 Pre-tax operating profit (loss) $ 767 (a) $ 321 $ 1,698 (b) $ (207 ) (c) $ 2,579 Income taxes — — — (710 ) (d) (710 ) Net income (loss) $ 767 $ 321 $ 1,698 $ (917 ) $ 1,869 Three months ended September 30, 2017 Net sales $ 1,865 $ 1,071 $ 266 $ (203 ) $ 2,999 Pre-tax operating profit (loss) $ 220 $ 200 $ 4 $ (149 ) (c) $ 275 Income taxes — — — (85 ) (d) (85 ) Net income (loss) $ 220 $ 200 $ 4 $ (234 ) $ 190 Oil Midstream Corporate and and and Gas Chemical Marketing Eliminations Total Nine months ended September 30, 2018 Net sales $ 7,874 $ 3,515 $ 2,359 $ (686 ) $ 13,062 Pre-tax operating profit (loss) $ 2,297 (a) $ 936 $ 2,127 (b) $ (584 ) (c) $ 4,776 Income taxes — — — (1,351 ) (d) (1,351 ) Net income (loss) $ 2,297 $ 936 $ 2,127 $ (1,935 ) $ 3,425 Nine months ended September 30, 2017 Net sales $ 5,607 $ 3,295 $ 747 $ (633 ) $ 9,016 Pre-tax operating profit (loss) $ 1,067 (e) $ 600 $ 76 (f) $ (481 ) (c) $ 1,262 Income taxes — — — (448 ) (d) (448 ) Net income (loss) $ 1,067 $ 600 $ 76 $ (929 ) $ 814 (a) Includes $196 million impairment related to proved properties and inventory in Qatar. (b) Includes $902 million gain on the sale of non-core domestic midstream assets. (c) Includes unallocated net interest expense, administration expense, environmental remediation and other items. (d) Includes all foreign and domestic income taxes from continuing operations. (e) Includes a gain on sale of domestic oil and gas assets, including South Texas, of $510 million . (f) Includes a non-cash fair value gain of $94 million on the Plains equity investment.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per share (EPS) was computed by dividing net income attributable to common stock, net of income allocated to participating securities, by the weighted-average number of common shares outstanding during each period, net of treasury shares and including vested but unissued shares and share units. The computation of diluted EPS reflects the additional dilutive effect of stock options and unvested stock awards. Occidental’s instruments containing rights to nonforfeitable dividends granted in stock-based awards are considered participating securities prior to vesting and, therefore, net income allocated to these participating securities has been deducted from earnings in computing basic and diluted EPS under the two-class method. The following table presents the calculation of basic and diluted EPS for the three and nine months ended September 30, 2018 , and 2017 (in millions, except per-share amounts): Three months ended September 30 Nine months ended September 30 2018 2017 2018 2017 Basic EPS Net Income $ 1,869 $ 190 $ 3,425 $ 814 Less: Net income allocated to participating securities (8 ) (1 ) (16 ) (4 ) Net Income, net of participating securities 1,861 189 3,409 810 Weighted average number of basic shares 761.7 765.5 764.3 764.9 Basic EPS $ 2.44 $ 0.25 $ 4.46 $ 1.06 Diluted EPS Net income, net of participating securities $ 1,861 $ 189 $ 3,409 $ 810 Weighted average number of basic shares 761.7 765.5 764.3 764.9 Dilutive effect of potentially dilutive securities 1.6 0.9 1.5 0.8 Total diluted weighted average common shares 763.3 766.4 765.8 765.7 Diluted EPS $ 2.44 $ 0.25 $ 4.45 $ 1.06

General (Policies)

General (Policies)	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	Occidental has made its disclosures in accordance with United States generally accepted accounting principles (GAAP) as they apply to interim reporting, and condensed or omitted, as permitted by the Securities and Exchange Commission’s rules and regulations, certain information and disclosures normally included in consolidated financial statements and the notes.
Accounting and Disclosure Changes	Accounting and Disclosure Changes In February 2018, the Financial Accounting Standards Board (FASB) released standards that allow the reclassification from accumulated other comprehensive income to retained earnings of stranded tax effects resulting from changes to U.S. federal tax law from the 2017 Tax Cuts and Jobs Act enacted in December 2017. Occidental early adopted this standard in the first quarter of 2018, resulting in the reclassification of $58 million in stranded tax effects from accumulated other comprehensive income to retained earnings. In the first quarter of 2018, Occidental adopted the new revenue recognition standard Topic 606 - Revenue from Contracts with Customers and related updates (ASC 606). The new standard requires more detailed disclosures related to the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Occidental adopted the standard using the modified retrospective method. The cumulative-effect adjustment to retained earnings upon adoption was not material. See Note 4 Revenue Recognition . In March 2017, FASB issued guidance related to presentation of net periodic pension cost and net periodic postretirement benefit cost. The rules became effective in the first quarter of 2018. These rules did not have a material impact to Occidental's financial statements upon adoption. In January 2017, FASB issued new guidance clarifying the definition of a business under the topic Business Combinations. The rules became effective in the first quarter of 2018, and did not have a material impact to Occidental's financial statements upon adoption. In November 2016, FASB issued new guidance related to the cash flow classification and presentation of the changes in restricted cash on the statement of cash flows. The rules became effective in the first quarter of 2018 and must be applied retrospectively. Occidental did not have restricted cash as of September 30, 2018, or December 31, 2017. In August 2016, FASB issued new guidance related to the classification of certain cash receipts and payments on the statement of cash flows. The rules were adopted for the first quarter of 2018 and resulted in the retrospective reclassification of $135 million of cash receipts from operating cash flows to investing cash flows for the nine months ended September 30, 2017, within the Statement of Cash Flows. In February 2016, FASB issued rules which require Occidental to recognize most leases, including operating leases, on the balance sheet. The new rules require lessees to recognize a right-of-use asset and lease liability for all leases with lease terms of more than 12 months. The lease liability represents the discounted obligation to make future minimum lease payments. The corresponding right-of-use asset includes the discounted obligation in addition to any upfront payment or cost incurred during contract execution of the lease. Recognition, measurement and presentation of expenses and cash flows arising from a lease will depend on classification as a finance or operating lease. Occidental is the lessee under various agreements for real estate, equipment, plants and facilities, aircraft and information technology hardware that are currently accounted for as operating leases. As a result, these new rules will increase reported assets and liabilities. Occidental will not be an early adopter of this standard. Occidental will apply the revised lease rules for its interim and annual reporting periods starting January 1, 2019, using a modified retrospective approach, including several optional practical expedients related to leases that commenced before the effective date. Occidental is currently evaluating the effect of these rules on its financial statements, training employees, working with third-party consultants and has developed an internal interim software solution for the identification, documentation, tracking and accounting of leases as a means of an adoption plan based on Occidental's population of leases under the revised definition of leases. Occidental is currently in the test phase and continues to evaluate existing and new lease contracts for compliance, including performing various procedures to assess completeness in population and evaluating right-of-way contract structures under the new guidance to determine future impacts from adoption. The quantitative impacts of the new standard are dependent on the leases in force at the time of adoption. As a result, the evaluation of the effect of the new standard is ongoing.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Schedule of reconciliation of revenue from customers to total net sales	The following table shows a reconciliation of revenue from customers to total net sales (in millions): Three Months Ended September 30, 2018 Nine months Ended September 30, 2018 Revenue from customers $ 4,257 $ 11,813 All other revenues (a) 959 1,249 Total net sales $ 5,216 $ 13,062 (a) Includes net marketing margin and chemical exchange contracts.
Schedule of revenue from customers by segment, product, and geographical area	Chemical and midstream revenues are shown by area based on the location of the sale (in millions): For the three months ended September 30, 2018 Revenue by Product United States Middle East Latin America Other International Total Oil and Gas Segment Oil $ 1,326 $ 1,016 $ 197 $ — $ 2,539 NGL 139 77 — — 216 Gas 47 80 5 — 132 Other 3 — (1 ) — 2 Segment Total $ 1,515 $ 1,173 $ 201 $ — $ 2,889 Chemical Segment $ 1,112 $ — $ 51 $ 21 $ 1,184 Midstream Segment Marketing and Trading $ 3 $ — $ — $ — $ 3 Gas Processing 148 108 — — 256 Pipelines 115 — — — 115 Power and Other 35 — — — 35 Segment Total $ 301 $ 108 $ — $ — $ 409 Intersegment Eliminations $ (225 ) $ — $ — $ — $ (225 ) Consolidated $ 2,703 $ 1,281 $ 252 $ 21 $ 4,257 For the nine months ended September 30, 2018 Revenue by Product United States Middle East Latin America Other International Total Oil and Gas Segment Oil $ 3,907 $ 2,507 $ 547 $ — $ 6,961 NGL 339 192 — — 531 Gas 141 218 12 — 371 Other 10 1 — — 11 Segment Total $ 4,397 $ 2,918 $ 559 $ — $ 7,874 Chemical Segment $ 3,294 $ — $ 154 $ 59 $ 3,507 Midstream Segment Marketing and Trading $ 11 $ — $ — $ — $ 11 Gas Processing 416 308 — — 724 Pipelines 310 — — — 310 Power and Other 73 — — — 73 Segment Total $ 810 $ 308 $ — $ — $ 1,118 Intersegment Eliminations $ (686 ) $ — $ — $ — $ (686 ) Consolidated $ 7,815 $ 3,226 $ 713 $ 59 $ 11,813

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Schedule of inventories	Inventories as of September 30, 2018 , and December 31, 2017 , consisted of the following (in millions): 2018 2017 Raw materials $ 69 $ 66 Materials and supplies 434 447 Finished goods 549 776 1,052 1,289 Revaluation to LIFO (43 ) (43 ) Total $ 1,009 $ 1,246

Environmental Liabilities and_2

Environmental Liabilities and Expenditures (Tables)	9 Months Ended
	Sep. 30, 2018
Environmental Remediation Obligations [Abstract]
Schedule of current and non-current environmental remediation reserves by categories of sites	Number of Sites Reserve Balance NPL sites 34 $ 453 Third-party sites 69 172 Occidental-operated sites 14 114 Closed or non-operated Occidental sites 29 137 Total 146 $ 876

Retirement and Postretirement_2

Retirement and Postretirement Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
Components of the net periodic benefit costs	The following tables set forth the components of the net periodic benefit costs for Occidental’s defined benefit plans for the three and nine months ended September 30, 2018 , and 2017 (in millions): Three months ended September 30 2018 2017 Net Periodic Benefit Costs Pension Benefit Postretirement Benefit Pension Benefit Postretirement Benefit Service cost $ — $ 5 $ 2 $ 5 Interest cost 4 8 4 9 Expected return on plan assets (7 ) — (6 ) — Recognized actuarial loss 2 2 2 3 Additional settlement cost 3 — — — Total $ 2 $ 15 $ 2 $ 17 Nine months ended September 30 2018 2017 Net Periodic Benefit Costs Pension Benefit Postretirement Benefit Pension Benefit Postretirement Benefit Service cost $ 4 $ 17 $ 6 $ 15 Interest cost 12 26 12 29 Expected return on plan assets (19 ) — (18 ) — Recognized actuarial loss 4 12 6 11 Additional settlement cost 3 — — — Total $ 4 $ 55 $ 6 $ 55

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	The following tables provide fair value measurement information for such assets and liabilities that are measured on a recurring basis as of September 30, 2018 , and December 31, 2017 (in millions): Fair Value Measurements at September 30, 2018: Embedded derivatives Level 1 Level 2 Level 3 Netting and Total Fair Liabilities: Accrued liabilities $ — $ 11 $ — $ — $ 11 Deferred credits and other liabilities - other $ — $ 53 $ — $ — $ 53 Fair Value Measurements at December 31, 2017: Embedded derivatives Level 1 Level 2 Level 3 Netting and Total Fair Liabilities: Accrued liabilities $ — $ 39 $ — $ — $ 39 Deferred credits and other liabilities - other $ — $ 147 $ — $ — $ 147

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of net sales related to the outstanding commodity derivative instruments	The following table summarizes the amounts reported in net sales related to the outstanding commodity derivatives not designated as hedging instruments as of September 30, 2018, and December 31, 2017. (in millions, except Long/(Short) volumes) 2018 2017 Unrealized gain (loss) on derivatives not designated as hedges Crude Oil Commodity Contracts $ (37 ) $ (47 ) Natural Gas Commodity Contracts $ (1 ) $ 1 Outstanding net volumes on derivatives not designated as hedges Crude Oil Commodity Contracts Volume (MMBL) 73 61 Natural Gas Commodity Contracts Volume (Bcf) (88 ) (47 )
Gross and net fair values of outstanding derivatives	The following table presents the gross and net fair values of Occidental’s outstanding derivatives as of September 30, 2018 , and December 31, 2017 (in millions): As of September 30, 2018 (in millions) Fair Value Measurements Using Netting (b) Total Fair Value Balance Sheet Location Level 1 Level 2 Level 3 Assets: Derivatives not designated as hedging instruments (a) Other current assets 1,210 631 — (1,235 ) 606 Long-term receivables and other assets, net 101 4 — (101 ) 4 Liabilities: Cash flow hedges (a) Accrued liabilities — 1 — — 1 Derivatives not designated as hedging instruments (a) Accrued liabilities 1,252 627 — (1,235 ) 644 Deferred credits and other liabilities - other 101 4 — (101 ) 4 As of December 31, 2017 (in millions) Fair Value Measurements Using Netting (b) Total Fair Value Balance Sheet Location Level 1 Level 2 Level 3 Assets: Cash flow hedges (a) Other current assets — 3 — — 3 Derivatives not designated as hedging instruments (a) Other current assets 485 227 — (517 ) 195 Long-term receivables and other assets, net 1 2 — (1 ) 2 Liabilities: Derivatives not designated as hedging instruments (a) Accrued liabilities 535 222 — (517 ) 240 Deferred credits and other liabilities - other 1 3 — (1 ) 3 (a) Fair values are presented at gross amounts, including when the derivatives are subject to master netting arrangements and presented on a net basis in the consolidated condensed balance sheets. (b) These amounts do not include collateral. As of September 30, 2018, no collateral received has been netted against derivative assets and collateral paid of $ 64 million has been netted against derivative liabilities. As of December 31, 2017, no collateral received has been netted against derivative assets and collateral paid of $ 54 million has been netted against derivative liabilities. Select clearinghouse and brokers require Occidental to post an initial margin deposit. Collateral deposited by Occidental, mainly for initial margin, of $ 73 million and $ 53 million as of September 30, 2018 and December 31, 2017, respectively, has not been reflected in these derivative fair -value tables. This collateral is included in other current assets in the consolidated condensed balance sheets.

Industry Segments (Tables)

Industry Segments (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule of industry segments	The following tables present Occidental’s industry segments (in millions): Oil Midstream Corporate and and and Gas Chemical Marketing Eliminations Total Three months ended September 30, 2018 Net sales $ 2,889 $ 1,185 $ 1,367 $ (225 ) $ 5,216 Pre-tax operating profit (loss) $ 767 (a) $ 321 $ 1,698 (b) $ (207 ) (c) $ 2,579 Income taxes — — — (710 ) (d) (710 ) Net income (loss) $ 767 $ 321 $ 1,698 $ (917 ) $ 1,869 Three months ended September 30, 2017 Net sales $ 1,865 $ 1,071 $ 266 $ (203 ) $ 2,999 Pre-tax operating profit (loss) $ 220 $ 200 $ 4 $ (149 ) (c) $ 275 Income taxes — — — (85 ) (d) (85 ) Net income (loss) $ 220 $ 200 $ 4 $ (234 ) $ 190 Oil Midstream Corporate and and and Gas Chemical Marketing Eliminations Total Nine months ended September 30, 2018 Net sales $ 7,874 $ 3,515 $ 2,359 $ (686 ) $ 13,062 Pre-tax operating profit (loss) $ 2,297 (a) $ 936 $ 2,127 (b) $ (584 ) (c) $ 4,776 Income taxes — — — (1,351 ) (d) (1,351 ) Net income (loss) $ 2,297 $ 936 $ 2,127 $ (1,935 ) $ 3,425 Nine months ended September 30, 2017 Net sales $ 5,607 $ 3,295 $ 747 $ (633 ) $ 9,016 Pre-tax operating profit (loss) $ 1,067 (e) $ 600 $ 76 (f) $ (481 ) (c) $ 1,262 Income taxes — — — (448 ) (d) (448 ) Net income (loss) $ 1,067 $ 600 $ 76 $ (929 ) $ 814 (a) Includes $196 million impairment related to proved properties and inventory in Qatar. (b) Includes $902 million gain on the sale of non-core domestic midstream assets. (c) Includes unallocated net interest expense, administration expense, environmental remediation and other items. (d) Includes all foreign and domestic income taxes from continuing operations. (e) Includes a gain on sale of domestic oil and gas assets, including South Texas, of $510 million . (f) Includes a non-cash fair value gain of $94 million on the Plains equity investment.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Calculation of basic and diluted EPS	The following table presents the calculation of basic and diluted EPS for the three and nine months ended September 30, 2018 , and 2017 (in millions, except per-share amounts): Three months ended September 30 Nine months ended September 30 2018 2017 2018 2017 Basic EPS Net Income $ 1,869 $ 190 $ 3,425 $ 814 Less: Net income allocated to participating securities (8 ) (1 ) (16 ) (4 ) Net Income, net of participating securities 1,861 189 3,409 810 Weighted average number of basic shares 761.7 765.5 764.3 764.9 Basic EPS $ 2.44 $ 0.25 $ 4.46 $ 1.06 Diluted EPS Net income, net of participating securities $ 1,861 $ 189 $ 3,409 $ 810 Weighted average number of basic shares 761.7 765.5 764.3 764.9 Dilutive effect of potentially dilutive securities 1.6 0.9 1.5 0.8 Total diluted weighted average common shares 763.3 766.4 765.8 765.7 Diluted EPS $ 2.44 $ 0.25 $ 4.45 $ 1.06

Asset Acquisitions, Dispositi_2

Asset Acquisitions, Dispositions and Other (Details) - USD ($)	1 Months Ended				3 Months Ended
	Sep. 30, 2018	Jul. 31, 2018	Mar. 31, 2018	Jan. 31, 2018	Dec. 31, 2018
4.2% senior notes due 2048
Asset Acquisitions, Dispositions and Other
Debt instrument issued			$ 1,000,000,000
Debt instrument interest rate stated percentage			4.20%
Net proceeds of debt			$ 985,000,000
1.50% senior notes due 2018
Asset Acquisitions, Dispositions and Other
Debt instrument interest rate stated percentage			1.50%
Repayment of debt			$ 500,000,000
2018 Credit Facility
Asset Acquisitions, Dispositions and Other
Debt instrument issued				$ 3,000,000,000
Credit facility term				5 years
Previously leased power and steam cogeneration facility
Asset Acquisitions, Dispositions and Other
Acquisition cost		$ 443,000,000
Disposed of by sale | Non-core Midstream assets
Asset Acquisitions, Dispositions and Other
Divestiture consideration	$ 2,600,000,000		150,000,000
Proceeds received for divested assets	2,400,000,000
Pre-tax net gain from divestiture	$ 902,000,000		$ 43,000,000
Scenario, Forecast | Previously leased power and steam cogeneration facility
Asset Acquisitions, Dispositions and Other
Payment to acquire previously leased facility					$ 60,000,000

Accounting and Disclosure Cha_2

Accounting and Disclosure Changes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2018	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash receipts from operating cash flows		$ 5,169	$ 3,440
Cash receipts from investing cash flows		$ (1,700)	(2,126)
Accounting Standards Update 2018-2
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of tax effects from accumulated other comprehensive income to retained earnings	$ 58
Accounting Standards Update 2016-15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash receipts from operating cash flows			(135)
Cash receipts from investing cash flows			$ 135

Revenue Recognition - Impact of

Revenue Recognition - Impact of Adoption (Details) - USD ($) $ in Millions	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue recognition
Retained earnings	$ 23,635		$ 21,935
Trade receivables, net	$ 6,000		$ 4,145
Topic 606 | Difference between Revenue Guidance in Effect before and after Topic 606
Revenue recognition
Retained earnings		$ 0

Revenue Recognition - Reconcili

Revenue Recognition - Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue from Contract with Customer [Abstract]
Revenue from customers	$ 4,257		$ 11,813
All other revenue	959		1,249
Total net sales	$ 5,216	$ 2,999	$ 13,062	$ 9,016

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation of revenue (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Disaggregation of revenue
Revenue from customers	$ 4,257	$ 11,813
United States
Disaggregation of revenue
Revenue from customers	2,703	7,815
Middle East
Disaggregation of revenue
Revenue from customers	1,281	3,226
Latin America
Disaggregation of revenue
Revenue from customers	252	713
Other International
Disaggregation of revenue
Revenue from customers	21	59
Intersegment Eliminations
Disaggregation of revenue
Revenue from customers	(225)	(686)
Intersegment Eliminations | United States
Disaggregation of revenue
Revenue from customers	(225)	(686)
Intersegment Eliminations | Middle East
Disaggregation of revenue
Revenue from customers	0	0
Intersegment Eliminations | Latin America
Disaggregation of revenue
Revenue from customers	0	0
Intersegment Eliminations | Other International
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment
Disaggregation of revenue
Revenue from customers	2,889	7,874
Oil and Gas Segment | Oil
Disaggregation of revenue
Revenue from customers	2,539	6,961
Oil and Gas Segment | NGL
Disaggregation of revenue
Revenue from customers	216	531
Oil and Gas Segment | Gas
Disaggregation of revenue
Revenue from customers	132	371
Oil and Gas Segment | Other
Disaggregation of revenue
Revenue from customers	2	11
Oil and Gas Segment | United States
Disaggregation of revenue
Revenue from customers	1,515	4,397
Oil and Gas Segment | United States | Oil
Disaggregation of revenue
Revenue from customers	1,326	3,907
Oil and Gas Segment | United States | NGL
Disaggregation of revenue
Revenue from customers	139	339
Oil and Gas Segment | United States | Gas
Disaggregation of revenue
Revenue from customers	47	141
Oil and Gas Segment | United States | Other
Disaggregation of revenue
Revenue from customers	3	10
Oil and Gas Segment | Middle East
Disaggregation of revenue
Revenue from customers	1,173	2,918
Oil and Gas Segment | Middle East | Oil
Disaggregation of revenue
Revenue from customers	1,016	2,507
Oil and Gas Segment | Middle East | NGL
Disaggregation of revenue
Revenue from customers	77	192
Oil and Gas Segment | Middle East | Gas
Disaggregation of revenue
Revenue from customers	80	218
Oil and Gas Segment | Middle East | Other
Disaggregation of revenue
Revenue from customers	0	1
Oil and Gas Segment | Latin America
Disaggregation of revenue
Revenue from customers	201	559
Oil and Gas Segment | Latin America | Oil
Disaggregation of revenue
Revenue from customers	197	547
Oil and Gas Segment | Latin America | NGL
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Latin America | Gas
Disaggregation of revenue
Revenue from customers	5	12
Oil and Gas Segment | Latin America | Other
Disaggregation of revenue
Revenue from customers	(1)	0
Oil and Gas Segment | Other International
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Other International | Oil
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Other International | NGL
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Other International | Gas
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Other International | Other
Disaggregation of revenue
Revenue from customers	0	0
Chemical Segment
Disaggregation of revenue
Revenue from customers	1,184	3,507
Chemical Segment | United States
Disaggregation of revenue
Revenue from customers	1,112	3,294
Chemical Segment | Middle East
Disaggregation of revenue
Revenue from customers	0	0
Chemical Segment | Latin America
Disaggregation of revenue
Revenue from customers	51	154
Chemical Segment | Other International
Disaggregation of revenue
Revenue from customers	21	59
Midstream Segment
Disaggregation of revenue
Revenue from customers	409	1,118
Midstream Segment | Marketing and Trading
Disaggregation of revenue
Revenue from customers	3	11
Midstream Segment | Gas Processing
Disaggregation of revenue
Revenue from customers	256	724
Midstream Segment | Pipelines
Disaggregation of revenue
Revenue from customers	115	310
Midstream Segment | Power and Other
Disaggregation of revenue
Revenue from customers	35	73
Midstream Segment | United States
Disaggregation of revenue
Revenue from customers	301	810
Midstream Segment | United States | Marketing and Trading
Disaggregation of revenue
Revenue from customers	3	11
Midstream Segment | United States | Gas Processing
Disaggregation of revenue
Revenue from customers	148	416
Midstream Segment | United States | Pipelines
Disaggregation of revenue
Revenue from customers	115	310
Midstream Segment | United States | Power and Other
Disaggregation of revenue
Revenue from customers	35	73
Midstream Segment | Middle East
Disaggregation of revenue
Revenue from customers	108	308
Midstream Segment | Middle East | Marketing and Trading
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Middle East | Gas Processing
Disaggregation of revenue
Revenue from customers	108	308
Midstream Segment | Middle East | Pipelines
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Middle East | Power and Other
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America | Marketing and Trading
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America | Gas Processing
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America | Pipelines
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America | Power and Other
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International | Marketing and Trading
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International | Gas Processing
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International | Pipelines
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International | Power and Other
Disaggregation of revenue
Revenue from customers	$ 0	$ 0

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Schedule of Cash Flow, Supplemental Disclosures [Line Items]
Interest paid	$ 298	$ 266
Foreign and State
Schedule of Cash Flow, Supplemental Disclosures [Line Items]
Income taxes paid	838	553
Domestic
Schedule of Cash Flow, Supplemental Disclosures [Line Items]
Tax refunds	$ 2	$ 756

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 69	$ 66
Materials and supplies	434	447
Finished goods	549	776
Inventories, gross	1,052	1,289
Revaluation to LIFO	(43)	(43)
Total	$ 1,009	$ 1,246

Environmental Liabilities and_3

Environmental Liabilities and Expenditures (Details) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Mar. 31, 2016mi	Sep. 30, 2016USD ($)	Sep. 30, 2018USD ($)sitecategory	Dec. 31, 2017USD ($)
Environmental remediation reserves
Number of Sites | site			146
Environmental remediation reserves, current, included in accrued liabilities			$ 136
Environmental remediation reserves, non-current, included in deferred credits and other liabilities - other			$ 740	$ 728
Number of non-NPL sites categories | category			3
Reserve Balance			$ 876
Environmental reserves, exceeding $ ten million, threshold value			$ 10
Environmental reserves, exceeding $ ten million, number of sites | site			16
Environmental reserves, range between zero to $ one million site category, number of sites | site			90
Expected expend funds of environmental reserves (as a percent)			5000.00%
Minimum period of expending second half of environmental reserves			10 years
Environmental remediation additional loss range			$ 1,100
Low end of range
Environmental remediation reserves
Period of expending first half of environmental reserves			3 years
High end of range
Environmental remediation reserves
Environmental reserves, range between zero to $ one million site category			$ 1
Period of expending first half of environmental reserves			4 years
NPL sites
Environmental remediation reserves
Number of Sites | site			34
Reserve Balance			$ 453
Third-party sites
Environmental remediation reserves
Number of Sites | site			69
Reserve Balance			$ 172
Occidental-operated sites
Environmental remediation reserves
Number of Sites | site			14
Reserve Balance			$ 114
Closed or non-operated Occidental sites
Environmental remediation reserves
Number of Sites | site			29
Reserve Balance			$ 137
Lower Passaic River
Environmental remediation reserves
Stretch of Lower Passaic river requiring remedial actions | mi	8.3
Stretch of Lower Passaic river not covered by remedial actions | mi	9
Clean-up estimated cost		$ 165

Lawsuits, Claims, Commitments_2

Lawsuits, Claims, Commitments and Contingencies (Details) - USD ($) $ in Billions	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Lawsuits, commitments and contingencies
Long-term purchase commitment	$ 2
Long-term purchase commitment, term	10 years
Arbitration filed by Andes Petroleum Ecuador Ltd
Lawsuits, commitments and contingencies
Proceeds from settlement			$ 1
Recovery of amount awarded in settlement amount (as a percent)			60.00%
Percentage of judgment amount claimed		40.00%
Own economic interest (as a percent)		60.00%

Retirement and Postretirement_3

Retirement and Postretirement Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Millions	Aug. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net Periodic Benefit Costs
Decrease to benefit obligation	$ 178
Pension Benefit
Net Periodic Benefit Costs
Service cost		$ 0	$ 2	$ 4	$ 6
Interest cost		4	4	12	12
Expected return on plan assets		(7)	(6)	(19)	(18)
Recognized actuarial loss		2	2	4	6
Additional settlement cost		3	0	3	0
Total		2	2	4	6
Postretirement Benefit
Net Periodic Benefit Costs
Service cost		5	5	17	15
Interest cost		8	9	26	29
Expected return on plan assets		0	0	0	0
Recognized actuarial loss		2	3	12	11
Additional settlement cost		0	0	0	0
Total		15	17	55	55
Defined benefit plans
Net Periodic Benefit Costs
Employer contributions		$ 2	$ 1	$ 4	$ 3

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Liabilities:
Carrying value of debt, net of unamortized discount	$ 10,400	$ 10,400	$ 9,900
Non-core Permian acreage
Liabilities:
Pre-tax impairment charges		42
Total Fair Value
Liabilities:
Debt estimated fair value	10,400	10,400	10,400
Recurring | Accrued liabilities
Liabilities:
Netting and Collateral	0	0	0
Recurring | Deferred credits and other liabilities - other
Liabilities:
Netting and Collateral	0	0	0
Recurring | Level 1 | Accrued liabilities
Liabilities:
Embedded derivatives	0	0	0
Recurring | Level 1 | Deferred credits and other liabilities - other
Liabilities:
Embedded derivatives	0	0	0
Recurring | Level 2 | Accrued liabilities
Liabilities:
Embedded derivatives	11	11	39
Recurring | Level 2 | Deferred credits and other liabilities - other
Liabilities:
Embedded derivatives	53	53	147
Recurring | Level 3 | Accrued liabilities
Liabilities:
Embedded derivatives	0	0	0
Recurring | Level 3 | Deferred credits and other liabilities - other
Liabilities:
Embedded derivatives	0	0	0
Recurring | Total Fair Value | Accrued liabilities
Liabilities:
Embedded derivatives	11	11	39
Recurring | Total Fair Value | Deferred credits and other liabilities - other
Liabilities:
Embedded derivatives	53	$ 53	147
Non recurring | Proved gas and oil properties
Liabilities:
Pre-tax impairment charges			$ 397
Qatar
Liabilities:
Pre-tax impairment charges	$ 196

Derivatives - Cash-Flow Hedges

Derivatives - Cash-Flow Hedges (Details) - Bcf	Sep. 30, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Natural gas held in storage (in cubic feet)	6	7
Forecast sale of natural gas from storage designated as cash-flow hedges (in cubic feet)	4	7

Derivatives - Not Designated as

Derivatives - Not Designated as Hedging Instruments (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)$ / MillionCubicFeet$ / BarrelBcfMMBbls	Dec. 31, 2017USD ($)$ / MillionCubicFeet$ / BarrelBcfMMBbls
Outstanding commodity derivatives contracts not designated as hedging instruments
Derivative instrument settlement period (within)	3 months
Not designated as hedging instruments | Crude oil
Outstanding commodity derivatives contracts not designated as hedging instruments
Weighted average sales price | $ / Barrel	69.98	57.38
Not designated as hedging instruments | Crude oil | Net sales
Outstanding commodity derivatives contracts not designated as hedging instruments
Unrealized gain (loss) on derivatives not designated as hedges	$ (37)	$ (47)
Not designated as hedging instruments | Natural gas
Outstanding commodity derivatives contracts not designated as hedging instruments
Weighted average sales price | $ / MillionCubicFeet	2.67	2.73
Not designated as hedging instruments | Natural gas | Net sales
Outstanding commodity derivatives contracts not designated as hedging instruments
Unrealized gain (loss) on derivatives not designated as hedges	$ (1)	$ 1
Not designated as hedging instruments | Long position | Crude oil
Outstanding commodity derivatives contracts not designated as hedging instruments
Outstanding net volumes on derivatives not designated as hedges (mmbls/bcf) | MMBbls	73	61
Not designated as hedging instruments | Short position | Natural gas
Outstanding commodity derivatives contracts not designated as hedging instruments
Outstanding net volumes on derivatives not designated as hedges (mmbls/bcf) | Bcf	88	47

Derivatives - Fair Value (Detai

Derivatives - Fair Value (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Gross and net fair values of outstanding derivatives (in millions)
Collateral received netted against derivative assets	$ 0	$ 0
Collateral paid netted against derivative liabilities	64,000,000	54,000,000
Collateral deposited with clearinghouses and brokers	73,000,000	53,000,000
Cash-flow hedges | Other current assets
Gross and net fair values of outstanding derivatives (in millions)
Netting, asset		0
Total net fair value, asset		3,000,000
Cash-flow hedges | Accrued liabilities
Gross and net fair values of outstanding derivatives (in millions)
Netting and collateral, liability	0
Total net fair value, liability	1,000,000
Cash-flow hedges | Level 1 | Other current assets
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross		0
Cash-flow hedges | Level 1 | Accrued liabilities
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	0
Cash-flow hedges | Level 2 | Other current assets
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross		3,000,000
Cash-flow hedges | Level 2 | Accrued liabilities
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	1,000,000
Cash-flow hedges | Level 3 | Other current assets
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross		0
Cash-flow hedges | Level 3 | Accrued liabilities
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	0
Not designated as hedging instruments | Other current assets
Gross and net fair values of outstanding derivatives (in millions)
Netting, asset	1,235,000,000	517,000,000
Total net fair value, asset	606,000,000	195,000,000
Not designated as hedging instruments | Long-term receivables and other assets, net
Gross and net fair values of outstanding derivatives (in millions)
Netting, asset	101,000,000	1,000,000
Total net fair value, asset	4,000,000	2,000,000
Not designated as hedging instruments | Accrued liabilities
Gross and net fair values of outstanding derivatives (in millions)
Netting and collateral, liability	(1,235,000,000)	(517,000,000)
Total net fair value, liability	644,000,000	240,000,000
Not designated as hedging instruments | Deferred credits and other liabilities - other
Gross and net fair values of outstanding derivatives (in millions)
Netting and collateral, liability	(101,000,000)	(1,000,000)
Total net fair value, liability	4,000,000	3,000,000
Not designated as hedging instruments | Level 1 | Other current assets
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross	1,210,000,000	485,000,000
Not designated as hedging instruments | Level 1 | Long-term receivables and other assets, net
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross	101,000,000	1,000,000
Not designated as hedging instruments | Level 1 | Accrued liabilities
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	1,252,000,000	535,000,000
Not designated as hedging instruments | Level 1 | Deferred credits and other liabilities - other
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	101,000,000	1,000,000
Not designated as hedging instruments | Level 2 | Other current assets
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross	631,000,000	227,000,000
Not designated as hedging instruments | Level 2 | Long-term receivables and other assets, net
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross	4,000,000	2,000,000
Not designated as hedging instruments | Level 2 | Accrued liabilities
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	627,000,000	222,000,000
Not designated as hedging instruments | Level 2 | Deferred credits and other liabilities - other
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	4,000,000	3,000,000
Not designated as hedging instruments | Level 3 | Other current assets
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross	0	0
Not designated as hedging instruments | Level 3 | Long-term receivables and other assets, net
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative asset, gross	0	0
Not designated as hedging instruments | Level 3 | Accrued liabilities
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	0	0
Not designated as hedging instruments | Level 3 | Deferred credits and other liabilities - other
Gross and net fair values of outstanding derivatives (in millions)
Commodity contract derivative liability, gross	$ 0	$ 0

Industry Segments (Details)

Industry Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)
Segment Information
Number of operating segments | segment			3
Net sales	$ 5,216	$ 2,999	$ 13,062	$ 9,016
Pre-tax operating profit (loss)	2,579	275	4,776	1,262
Income taxes	(710)	(85)	(1,351)	(448)
Net income (loss)	1,869	190	3,425	814
Gain on sale of assets	926	86	969	598
Qatar
Segment Information
Pre-tax impairment charges	196
South Texas operations | Domestic oil and gas assets
Segment Information
Gain on sale of assets				510
Oil and Gas | Qatar
Segment Information
Pre-tax impairment charges	196		196
Oil and Gas | South Texas operations | Domestic oil and gas assets
Segment Information
Gain on sale of assets		510
Midstream and Marketing | Non-core Midstream assets
Segment Information
Pre-tax gain on sale of domestic non-core midstream assets			902
Operating segments | Oil and Gas
Segment Information
Net sales	2,889	1,865	7,874	5,607
Pre-tax operating profit (loss)	767	220	2,297	1,067
Income taxes	0	0	0	0
Net income (loss)	767	220	2,297	1,067
Operating segments | Chemical
Segment Information
Net sales	1,185	1,071	3,515	3,295
Pre-tax operating profit (loss)	321	200	936	600
Income taxes	0	0	0	0
Net income (loss)	321	200	936	600
Operating segments | Midstream and Marketing
Segment Information
Net sales	1,367	266	2,359	747
Pre-tax operating profit (loss)	1,698	4	2,127	76
Income taxes	0	0	0	0
Net income (loss)	1,698	4	2,127	76
Operating segments | Midstream and Marketing | Equity investment
Segment Information
Non-cash fair value gain		94		94
Corporate and Eliminations
Segment Information
Net sales	(225)	(203)	(686)	(633)
Pre-tax operating profit (loss)	(207)	(149)	(584)	(481)
Income taxes	(710)	(85)	(1,351)	(448)
Net income (loss)	$ (917)	$ (234)	$ (1,935)	$ (929)

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Basic EPS
Net income (loss)	$ 1,869	$ 190	$ 3,425	$ 814
Less: Net income allocated to participating securities	(8)	(1)	(16)	(4)
Net Income, net of participating securities	$ 1,861	$ 189	$ 3,409	$ 810
Weighted average number of basic shares (in shares)	761.7	765.5	764.3	764.9
Basic EPS (in dollars per share)	$ 2.44	$ 0.25	$ 4.46	$ 1.06
Diluted EPS
Net income, net of participating securities	$ 1,861	$ 189	$ 3,409	$ 810
Weighted average number of basic shares (in shares)	761.7	765.5	764.3	764.9
Dilutive effect of potentially dilutive securities (in shares)	1.6	0.9	1.5	0.8
Total diluted weighted average common shares (in shares)	763.3	766.4	765.8	765.7
Diluted EPS (in dollars per share)	$ 2.44	$ 0.25	$ 4.45	$ 1.06