Environmental Liabilities and Expenditures (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($) site
Environmental Liabilities and Expenditures
Environmental remediation reserves, current, included in accrued liabilities	$ 79
Environmental remediation reserves, noncurrent, included in deferred credits and other liabilities - other	$ 236
Environmental remediation reserves
Number of Sites | site	148
Reserve Balance	$ 315
Environmental reserves, exceeding $ ten million, threshold value	$ 10
Environmental reserves, range between zero to $ one million site category, number of sites | site	104
Minimum period of expending second half of environmental reserves	10 years
Low end of range
Environmental remediation reserves
Environmental reserves, exceeding $ ten million, number of sites | site	10
Environmental reserves, range between zero to $ one million site category	$ 1
Period of expending first half of environmental reserves	3 years
High end of range
Environmental remediation reserves
Period of expending first half of environmental reserves	4 years
Environmental remediation additional loss range	$ 395
NPL sites
Environmental remediation reserves
Number of Sites | site	33
Reserve Balance	$ 21
Third-party sites
Environmental remediation reserves
Number of Sites | site	66
Reserve Balance	$ 101
Occidental-operated sites
Environmental remediation reserves
Number of Sites | site	18
Reserve Balance	$ 102
Closed or non-operated Occidental sites
Environmental remediation reserves
Number of Sites | site	31
Reserve Balance	$ 91