Discontinued Operations - Discontinued operations results of operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lease revenue	$ 3,598	$ 3,485
Depreciation, depletion and amortization	1,468	1,487
Operating expenses	925	882
Property taxes	737	753
Total operating profit	794	1,355
Interest expense	(51)	(588)
Income before income taxes	2,100	2,313
Provision for income taxes	601	672
Income from discontinued operations	$ 0	$ 86
Earnings per common share:
Basic earnings per common share Discontinued operations	$ 0.00	$ 0.01
Diluted earnings per common share discontinued operations	$ 0.00	$ 0.01
Discontinued Operations, Disposed of by Sale [Member]
Lease revenue		$ 238
Depreciation, depletion and amortization		29
Operating expenses		95
Property taxes		20
Management company indirect		0
Corporate expenses		0
Total cost of operations		144
Total operating profit		94
Interest expense		0
Gain on sale of buildings		23
Income before income taxes		117
Provision for income taxes		31
Income from discontinued operations		$ 86
Earnings per common share:
Basic earnings per common share Discontinued operations		$ 0.01
Diluted earnings per common share discontinued operations		$ 0.01