Environmental Liabilities and Expenditures (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 site
Environmental Liabilities and Expenditures
Environmental remediation reserves, current, included in accrued liabilities	$ 80
Environmental remediation reserves, noncurrent, included in deferred credits and other liabilities - other	247
Environmental remediation reserves.
Number of Sites	161
Environmental remediation reserves	327
Environmental reserves, exceeding $ ten million, threshold value	10
Environmental reserves, exceeding $ ten million, number of sites	11
Environmental reserves, range between zero to $ one million site category, number of sites	114
Minimum period of expending second half of environmental reserves	10 years
Environmental remediation additional loss range	375
Low end of range
Environmental remediation reserves.
Environmental reserves, range between zero to $ one million site category	0
Period of expending first half of environmental reserves	3 years
High end of range
Environmental remediation reserves.
Environmental reserves, range between zero to $ one million site category	1
Period of expending first half of environmental reserves	4 years
NPL sites
Environmental remediation reserves.
Number of Sites	33
Environmental remediation reserves	52
Third-party sites
Environmental remediation reserves.
Number of Sites	76
Environmental remediation reserves	74
Occidental-operated sites
Environmental remediation reserves.
Number of Sites	22
Environmental remediation reserves	121
Closed or non-operated Occidental sites
Environmental remediation reserves.
Number of Sites	30
Environmental remediation reserves	$ 80