ACQUISITIONS, DISPOSITIONS AND OTHER TRANSACTIONS (Details 4) (Libya activity, USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2011
Libya activity
Acquisitions, dispositions and other transactions
Capitalized and suspended exploration costs written off	$ 35

Capitalized and suspended exploration costs incurred to date that were written off due to ceased exploration activity.

No definition available.

Name:	oxy_CapitalizedSuspendedExploratoryWellCostWrittenOff
Namespace Prefix:	oxy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration