Litigation And Other Contingencies (Narrative) (Details) - USD ($) |
Oct. 09, 2014 |
Oct. 24, 2011 |
Jun. 27, 2007 |
May. 01, 2007 |
|---|---|---|---|---|
| Mobil Cerro Negro, Ltd. (MCN) [Member] | Expropriation of Assets [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Percentage ownership interest in Cerro Negro Project | 41.67% | 41.67% | ||
| Interest compounded annually from date of expropriation until date of payment in full | 3.25% | |||
| Final award related to Cerro Negro arbitration | $ 1,600,000,000 | |||
| Earlier Cerro Negro award for breach of contractual obligations | $ 908,000,000 | |||
| Production Sharing Contract (PSC) [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Percent interest in Erha block PSC | 56.25% | |||
| Pending Or Threatened Litigation [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Amount of award relating to excess lifting of crude oil | $ 1,800,000,000 | |||
| Accrued interest relating to award for excess lifting of crude oil | $ 234,000,000 |