Derivatives - Cash Flow Hedges Outstanding (Details) - ft³ ft³ in Billions	Sep. 30, 2016	Dec. 31, 2015
Derivatives
Natural gas held in storage (in cubic feet)	7	13
Forecast sale of natural gas from storage designated as cash-flow hedges (in cubic feet)	7	14

This element represents the forecast sales volume of natural gas from storage in billion cubic feet designated as cash flow hedges.

No definition available.

Name:	oxy_DesignatedForecastSaleOfNaturalGasAsCashFlowHedges
Namespace Prefix:	oxy_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	instant