Asset Retirement Obligations (Details) $ in Thousands |
3 Months Ended |
|---|---|
|
Mar. 31, 2018
USD ($)
| |
| Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | |
| Asset retirement obligations at January 1, 2018 | $ 12,161 |
| Liabilities acquired | 16 |
| Liabilities incurred | 253 |
| Liabilities divested | (253) |
| Accretion expense | 189 |
| Revisions to estimated cash flows | (10) |
| Asset retirement obligations at March 31, 2018 | $ 12,356 |