Suspended Wells Net Changes in Well Costs (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Net changes in suspended Exploratory well costs | |||
| Beginning balance | $ 856,000,000 | $ 853,000,000 | $ 1,063,000,000 |
| Additions pending the determination of proved reserves | 239,000,000 | 140,000,000 | 118,000,000 |
| Reclassifications to proved properties | (11,000,000) | (37,000,000) | (66,000,000) |
| Sales of suspended wells | (54,000,000) | (93,000,000) | 0 |
| Charged to dry hole expense | (10,000,000) | (7,000,000) | (262,000,000) |
| Ending balance | $ 1,020,000,000 | $ 856,000,000 | $ 853,000,000 |