Annual report pursuant to Section 13 and 15(d)

Property and Equipment - Schedule of Asset Retirement Obligation (Details)

v3.20.4
Property and Equipment - Schedule of Asset Retirement Obligation (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]      
Asset retirement obligation, beginning of period $ 60,355 $ 79,952  
Liabilities incurred 2,358 5,935  
Liabilities settled 0 (273)  
Asset retirement obligation removed due to divestiture (2,213) (30,146) $ 0
Accretion expense 3,066 3,939 4,119
Revisions in estimated cash flows 0 948  
Total asset retirement obligation as of end of period 63,566 60,355 $ 79,952
Less: amounts reclassified to liabilities subject to compromise (63,566) 0  
Total asset retirement obligation reflected as non-current liabilities $ 0 $ 60,355