Business Segments - Business Segments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenue	$ 5,319,000	$ 6,474,000	$ 5,289,000
Depreciation, depletion, and amortization	456,000	522,000	1,799,000
Income from operations	(646,000)	264,000	(3,000)
Identifiable assets net of DDA	23,898,000	24,398,000	24,132,000
Impairment of oil and gas assets[Member]
Segment Reporting Information [Line Items]
Depreciation, depletion, and amortization			695,000
Gas gathering, compression and equipment rental [Member]
Segment Reporting Information [Line Items]
Revenue	125,000	136,000	126,000
Depreciation, depletion, and amortization	1,000	1,000	13,000
Income from operations	92,000	86,000	73,000
Identifiable assets net of DDA	8,000	10,000	5,000
Commercial real estate investment [Member]
Segment Reporting Information [Line Items]
Revenue	248,000	232,000	274,000
Depreciation, depletion, and amortization	47,000	47,000	48,000
Income from operations	22,000	(11,000)	43,000
Subtotal [Member]
Segment Reporting Information [Line Items]
Income from operations	1,950,000	3,050,000	2,475,000
Identifiable assets net of DDA	3,392,000	4,782,000	5,950,000
Corporate and other [Member]
Segment Reporting Information [Line Items]
Income from operations	(2,596,000)	(2,786,000)	(2,478,000)
Identifiable assets net of DDA	20,506,000	19,616,000	18,182,000
Commercial real estate investment
Segment Reporting Information [Line Items]
Identifiable assets net of DDA	1,276,000	1,323,000	1,371,000
Oil and gas exploration, acquisition, production and operations [Member]
Segment Reporting Information [Line Items]
Revenue	4,946,000	6,106,000	4,889,000
Depreciation, depletion, and amortization	408,000	461,000	1,043,000
Income from operations	1,836,000	2,975,000	2,359,000
Identifiable assets net of DDA	$ 2,108,000	$ 3,449,000	$ 4,574,000