Environmental Liabilities and Expenditures (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012 Y 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	250
Environmental remediation reserves.
Number of Sites	159
Environmental remediation reserves	329
Environmental reserves, exceeding $ ten million, threshold value	10
Environmental reserves, exceeding $ ten million, number of sites	10
Environmental reserves, range between zero to $ one million site category, number of sites	110
Period of expending first half of environmental reserves (in years)	4
Minimum period of expending second half of environmental reserves (in years)	10
Environmental remediation additional loss range	385
Low end of range
Environmental remediation reserves.
Environmental reserves, range between zero to $ one million site category	0
High end of range
Environmental remediation reserves.
Environmental reserves, range between zero to $ one million site category	1
NPL sites
Environmental remediation reserves.
Number of Sites	35
Environmental remediation reserves	53
Third-party sites
Environmental remediation reserves.
Number of Sites	73
Environmental remediation reserves	84
Occidental-operated sites
Environmental remediation reserves.
Number of Sites	22
Environmental remediation reserves	110
Closed or non-operated Occidental sites
Environmental remediation reserves.
Number of Sites	29
Environmental remediation reserves	$ 82