Asset Retirement Obligations (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
| Asset retirement obligations, beginning of period | $ 16,874 | $ 13,895 |
| Liabilities incurred | 589 | 1,393 |
| Liabilities on acquired properties | 147 | 1,167 |
| Liabilities settled | (578) | (1,361) |
| Accretion expense | 1,128 | 912 |
| Revision to estimated cash flows | (1,151) | 868 |
| Asset retirement obligations, end of period | $ 17,009 | $ 16,874 |