Supplemental Reserve Information (Details 3) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in the standardized measure of discounted future net cash flows:
Beginning of the year	$ 11,051,000	$ 9,794,000	$ 6,023,000
Sales of oil and gas, net of production costs	(1,950,000)	(3,194,000)	(2,318,000)
Net changes in prices and production costs	(3,558,000)	2,171,000	721,000
Extensions, discoveries, additions less related costs	17,000	475,000	211,000
Development costs incurred	68,000	181,000	415,000
Net changes in future development cost
Revisions of previous quantity estimates	203,000	284,000	698,000
Net change in purchase and sales of minerals in place	20,000	33,000	3,103,000
Accretion of discount	1,105,000	979,000	602,000
Net change in income taxes	(276,000)	(103,000)	(250,000)
Other	(582,000)	431,000	589,000
End of the year	$ 6,098,000	$ 11,051,000	$ 9,794,000