Environmental Liabilities and Expenditures (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 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	(264)
Environmental remediation reserves.
Number of Sites	160
Environmental remediation reserves	343
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	109
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	380
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	36
Environmental remediation reserves	58
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	117
Closed or non-operated Occidental sites
Environmental remediation reserves.
Number of Sites	29
Environmental remediation reserves	$ 84