| Document and Entity Information | Aug. 08, 2019 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Aug. 8, 2019 |
| Entity Registrant Name | Anadarko Petroleum Corp |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-08968 |
| Entity Tax Identification Number | 76-0146568 |
| Entity Address, Address Line One | 1201 Lake Robbins Dr. |
| Entity Address, City or Town | The Woodlands |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77380 |
| City Area Code | 832 |
| Local Phone Number | 636-1000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | APC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000773910 |
