Litigation And Other Contingencies (Narrative) (Details) - USD ($) $ in Millions |
Mar. 09, 2017 |
Oct. 09, 2014 |
Oct. 24, 2011 |
Jun. 27, 2007 |
|---|---|---|---|---|
| Mobil Cerro Negro, Ltd. (MCN) [Member] | Expropriation of Assets [Member] | ||||
| Litigation And Other Contingencies [Line Items] | ||||
| Percentage ownership interest in Cerro Negro Project | 41.67% | |||
| Cerro Negro award for breach of contractual obligations | $ 908 | |||
| Annulled Portion Of Award For Cerro Negro Project | $ 1,400 | |||
| Retained and paid portion of award for Cerro Negro and La Ceiba Projects | $ 260 | |||
| Nigeria Production Sharing Contract Litigation [Member] | ||||
| Litigation And Other Contingencies [Line Items] | ||||
| Percent interest in Erha block PSC | 56.25% | |||
| Pending Or Threatened Litigation [Member] | ||||
| Litigation And Other Contingencies [Line Items] | ||||
| Amount of award relating to excess lifting of crude oil | $ 1,800 | |||
| Accrued interest relating to award for excess lifting of crude oil | $ 234 |