Accounting For Suspended Exploratory Well Costs (Schedule Of Number Of Projects With Suspended Exploratory Well Costs) (Details) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Accounting For Suspended Exploratory Well Costs [Abstract] | |||
| Number of projects with first capitalized well drilled in the preceding 12 months | 4 | 8 | 8 |
| Number of projects that have exploratory well costs capitalized for a period of greater than 12 months | 55 | 53 | 50 |
| Total | 59 | 61 | 58 |