Results of operations associated with discontinued operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Lease Revenues	$ 21,755	$ 14,106	$ 14,318
Operating expenses	6,219	3,333	4,134
Property taxes	3,751	2,826	2,941
Management company indirect	3,168	2,951	2,514
Corporate expenses	3,071	3,511	2,556
Total operating profit	2,274	5,134	5,756
Interest expense	2,304	1,100	1,054
Income before income taxes	50,375	14,929	11,784
Provision for (benefit from) income taxes	10,281	3,207	2,962
Income from discontinued operations	$ 0	$ 0	6,856
Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Lease Revenues			460
Depreciation, depletion and amortization			17
Operating expenses			248
Property taxes			41
Management company indirect			0
Corporate expenses			0
Total cost of operations			306
Total operating profit			154
Interest expense			0
Gain on sale of buildings			9,244
Income before income taxes			9,398
Provision for (benefit from) income taxes			2,542
Income from discontinued operations			$ 6,856