Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Principles - Asset Retirement Obligations (Details)

v3.20.4
Summary of Significant Accounting Principles - Asset Retirement Obligations (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2020
USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]  
Liability acquired $ 76,133
Accretion expense 97
Liability settled (2)
Balance at end of period $ 76,228