Cover Page	9 Months Ended
	Sep. 30, 2019 shares
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	1-9210
Entity Registrant Name	OCCIDENTAL PETROLEUM CORP /DE/
Entity Central Index Key	0000797468
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	95-4035997
Entity Address, Address Line One	5 Greenway Plaza, Suite 110
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77046
City Area Code	713
Local Phone Number	215-7000
Title of 12(b) Security	Common Stock, $0.20 par value
Trading Symbol	OXY
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	893,317,470