XML 90 R48.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Summary of Significant Accounting Policies - Summary of Changes in Asset Retirement Obligations (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]      
Asset retirement obligations, beginning of year $ 26,884 $ 27,170  
Additional liabilities incurred 1,490 2,111  
Dispositions of wells (339) (3,557)  
Accretion expense 1,465 1,422 $ 971
Liabilities settled upon plugging and abandoning wells (484) (262)  
Revision of estimates (5,577) 0  
Asset retirement obligations, end of year $ 23,439 $ 26,884 $ 27,170