Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Asset Retirement Obligations) (Details)

v3.10.0.1
Summary of Significant Accounting Policies (Asset Retirement Obligations) (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2018
USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]  
Balance at beginning of period $ 0
Liability acquired 38,686
Liability incurred 113
Accretion expense 1,662
Liability settled 0
Balance at end of period $ 40,461