Property, Plant And Equipment And Asset Retirement Obligations (Property, Plant And Equipment) (Details) - USD ($) $ in Millions |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|---|---|---|---|
| Property, Plant and Equipment [Line Items] | |||
| Property, Plant and Equipment, Cost | $ 447,337 | $ 446,789 | |
| Property, Plant and Equipment, Net | 251,605 | 252,668 | $ 243,650 |
| Upstream [Member] | |||
| Property, Plant and Equipment [Line Items] | |||
| Property, Plant and Equipment, Cost | 347,821 | 347,170 | |
| Property, Plant and Equipment, Net | 203,822 | 205,308 | |
| Downstream [Member] | |||
| Property, Plant and Equipment [Line Items] | |||
| Property, Plant and Equipment, Cost | 50,742 | 53,327 | |
| Property, Plant and Equipment, Net | 21,330 | 22,639 | |
| Chemical [Member] | |||
| Property, Plant and Equipment [Line Items] | |||
| Property, Plant and Equipment, Cost | 32,481 | 30,717 | |
| Property, Plant and Equipment, Net | 16,247 | 14,918 | |
| Other [Member] | |||
| Property, Plant and Equipment [Line Items] | |||
| Property, Plant and Equipment, Cost | 16,293 | 15,575 | |
| Property, Plant and Equipment, Net | $ 10,206 | $ 9,803 |