Income Taxes - Deferred Tax (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Depletion and amortization	$ 152,000	$ 282,000
Expired leasehold	145,000	134,000
Other, net	4,000	4,000
Depreciation	47,000
Net deferred tax asset	348,000	420,000
Deferred tax liabilities
Intangible drilling costs	(292,000)	(482,000)
Depreciation		(24,000)
Total deferred tax liability	(292,000)	(506,000)
Net deferred tax liability		(86,000)
Net deferred tax asset	$ 56,000