Environmental Liabilities and Expenditures (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 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	(257)
Environmental remediation reserves.
Number of Sites	164
Environmental remediation reserves	336
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	114
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	370
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	37
Environmental remediation reserves	56
Third-party sites
Environmental remediation reserves.
Number of Sites	76
Environmental remediation reserves	82
Occidental-operated sites
Environmental remediation reserves.
Number of Sites	22
Environmental remediation reserves	114
Closed or non-operated Occidental sites
Environmental remediation reserves.
Number of Sites	29
Environmental remediation reserves	$ 84