Annual report pursuant to Section 13 and 15(d)

Asset Retirement Obligations (Narrative) (Details)

v3.20.1
Asset Retirement Obligations (Narrative) (Details) - USD ($)
$ in Thousands
1 Months Ended 12 Months Ended
Dec. 31, 2019
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Asset Retirement Obligations [Abstract]        
Asset retirement obligation, revision of estimate $ (400) $ (379) $ (6,527) $ 703