Asset Retirement Obligations and Accrued Environmental Costs (Tables) |
12 Months Ended |
|---|---|
Dec. 31, 2019 | |
| Asset Retirement Obligation Disclosure [Abstract] | |
| Asset retirement obligations and accrued environmental costs | Note 10—Asset Retirement Obligations and Accrued Asset retirement obligations and accrued environmental Millions of Dollars 2019 2018 Asset retirement obligations $ 6,206 7,908 Accrued environmental costs 171 178 Total asset retirement obligations and accrued environmental costs 6,377 8,086 Asset retirement obligations and accrued environmental (1,025) (398) Long-term asset retirement obligations and accrued $ 5,352 7,688 |
| Changes in overall asset retirement obligation changed | During 2019 and 2018, our overall ARO changed Millions of Dollars 2019 2018 Balance at January 1 $ 7,908 7,798 Accretion of discount 322 348 New obligations 155 657 Changes in estimates of existing obligations 50 (266) Spending on existing obligations (229) (228) Property dispositions (1,920) (161) Foreign currency translation (80) (240) Balance at December 31 $ 6,206 7,908 |