| Component: (Network and Table) | |
|---|---|
| Network | 2418409 - Disclosure - Pension Plans, Other Postretirement Benefits, and Defined-Contribution Plans - Weighted-Average Assumptions for Benefit Obligations and Net Periodic Benefit Cost Table (Detail) (http://www.anadarko.com/role/PensionPlansOtherPostretirementBenefitsAndDefinedContributionPlansWeightedAverageAssumptionsForBenefitObligationsAndNetPeriodicBenefitCostTableDetail) |
| Table | Schedule of Defined Benefit Plans Disclosures [Table] |
| Reporting Entity [Axis] | 0000773910 (http://www.sec.gov/CIK) |
| Defined Benefit Plan Disclosure [Line Items] | Period [Axis] | |||||
|---|---|---|---|---|---|---|
2016-01-01 - 2016-12-31 | 2015-01-01 - 2015-12-31 | 2014-01-01 - 2014-12-31 | ||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] | Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] | Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] | ||||
| Pension Plans, Defined Benefit [Member] | Other Postretirement Benefit Plan [Member] | Pension Plans, Defined Benefit [Member] | Other Postretirement Benefit Plan [Member] | Pension Plans, Defined Benefit [Member] | Other Postretirement Benefit Plan [Member] | |
Discount rate | ||||||
Rates of increase in compensation levels | ||||||
Discount rate | ||||||
Long-term rate of return on plan assets | ||||||
Rates of increase in compensation levels | ||||||