Environmental Liabilities and Expenditures (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) site
Environmental Liabilities and Expenditures
Environmental remediation reserves, current, included in accrued liabilities	$ 70
Environmental remediation reserves, noncurrent, included in deferred credits and other liabilities - other	$ 314
Environmental remediation reserves
Number of Sites | site	149
Reserve Balance	$ 384
Environmental reserves, exceeding $ ten million, threshold value	$ 10
Environmental reserves, range between zero to $ one million site category, number of sites | site	99
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	12
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	$ 370
NPL sites
Environmental remediation reserves
Number of Sites | site	34
Reserve Balance	$ 28
Third-party sites
Environmental remediation reserves
Number of Sites | site	66
Reserve Balance	$ 127
Occidental-operated sites
Environmental remediation reserves
Number of Sites | site	18
Reserve Balance	$ 105
Closed or non-operated Occidental sites
Environmental remediation reserves
Number of Sites | site	31
Reserve Balance	$ 124