XML 53 R85.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Asset Retirement Obligations (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
Balance, Beginning of Year $ 38,554 $ 204,070
Obligations Divested 0 (196,643)
Accretion Expense 9,458 9,874
Obligations Incurred 2,933 4,795
Obligations Settled (4,231) (5,323)
Revisions in Estimated Cash Flows 21,740 21,781
Balance, End of Year $ 68,454 $ 38,554