SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
RISKS AND UNCERTAINTIES
Assets, relating to operations in countries outside North America	$ 9,800
Net sales, relating to operations in countries outside North America	4,900
CASH AND CASH EQUIVALENTS
Total cash equivalents	2,900	$ 3,400
RESTRICTED CASH
Restricted cash	$ 1,193	4,019
Restricted cash useage term (in months)	18 months
PROPERTY, PLANT AND EQUIPMENT
Maximum time period after which costs of exploratory wells are charged to expense if determination of proved reserves has not been made	12 months
Net capitalized costs attributable to unproved properties	$ 300	2,000
Capitalized exploratory well costs for the years ended December 31:
Balance - Beginning of Year	141	140	$ 124
Additions to capitalized exploratory well costs pending the determination of proved reserves	82	462	337
Reclassifications to property, plant and equipment based on the determination of proved reserves	(78)	(423)	(271)
Spin-off of California Resources		(17)
Capitalized exploratory well costs charged to expense	(75)	(21)	(50)
Balance - End of Year	70	141	140
ACCRUED LIABILITIES-CURRENT
Accrued liabilities for accrued payroll, commissions and related expenses	$ 188	361
ENVIRONMENTAL LIABILITIES AND EXPENDITURES
Minimum period of investigation and cleanup for Comprehensive Environmental Response, Compensation and Liability Act National Priorities List sites	10 years
Reimbursements and recoveries of environmental remediation costs accrued to income	$ 13	0	0
ASSET RETIREMENT OBLIGATIONS
Asset retirement obligation, included in deferred credits and other liabilities-other	1,000	1,000
For the years ended December 31
Beginning balance	1,091	1,332
Liabilities incurred - capitalized to PP&E	46	57
Liabilities settled and paid	(35)	(78)
Accretion expense	54	69
Acquisitions, dispositions and other - changes in PP&E	(209)	(11)
Spin-off of California Resources		(399)
Revisions to estimated cash flows - changes in PP&E	177	121
Ending balance	1,124	1,091	1,332
SUPPLEMENTAL CASH FLOW INFORMATION
Interest Paid	246	219	238
Capitalized interest	$ 138	180	137
Low end of range
Summary of significant accounting policies
The estimated useful lives of Occidental's chemical assets	3 years
DERIVATIVE INSTRUMENTS
Range used to determine if derivative instrument is effective	80.00%
High end of range
Summary of significant accounting policies
The estimated useful lives of Occidental's chemical assets	50 years
DERIVATIVE INSTRUMENTS
Range used to determine if derivative instrument is effective	125.00%
Continuing operations
SUPPLEMENTAL CASH FLOW INFORMATION
United States federal, state and foreign income taxes paid for continuing operations	$ 1,000	2,900	1,800
Production, property and other taxes paid	$ 445	$ 610	$ 606