LAWSUITS, CLAIMS, COMMITMENTS AND CONTINGENCIES _Lega Matters (Details)	12 Months Ended
Dec. 31, 2017
LAWSUITS, CLAIMS, COMMITMENTS AND CONTINGENCIES
Claim to a settlement amount (as a percent)	40.00%

Percentage of claim to a settlement amount of a legal case.

No definition available.

Name:	oxy_PercentageOfClaimToSettlementAmount
Namespace Prefix:	oxy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration