Supplemental Information on Oil and Natural Gas Operations (Unaudited) (Details Textual) MBoe in Thousands	12 Months Ended
	Dec. 31, 2020 MBoe Well	Dec. 31, 2019 MBoe Well	Dec. 31, 2018 MBoe Well Location
Extractive Industries [Abstract]
Unweighted average of first day of month prices	12 months	12 months	12 months
Number of wells, net | Well			92
Number of oil wells reduced | Well	269	314
Revisions of previous estimates | MBoe	(1,590)	(3,373)	1,759
Purchase of reserves in place | MBoe	72	56	50
Number of new proved undeveloped locations | Location			225