CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 4,047,000	$ 40,094,000	$ 11,722,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	11,462,000	12,946,000	6,050,000
Deferred income taxes	1,813,000	7,941,000	5,995,000
Gain on remeasurement of invest in real estate partnership	0	(51,139,000)	0
Equity in loss of joint ventures	5,721,000	5,754,000	5,690,000
Gain on sale of equipment and property	(904,000)	(880,000)	(9,184,000)
Stock-based compensation	1,569,000	1,111,000	1,372,000
Realized (gain) loss on available for sale investments	0	0	(298,000)
Deferred debt issuance cost write-off	0	0	902,000
Net changes in operating assets and liabilities:
Accounts receivable	(373,000)	837,000	(377,000)
Deferred costs and other assets	(1,972,000)	(346,000)	27,000
Accounts payable and accrued liabilities	(276,000)	1,888,000	956,000
Income taxes payable and receivable	1,121,000	3,518,000	(5,125,000)
Other long-term liabilities	130,000	518,000	883,000
Net cash provided by operating activities	22,338,000	22,242,000	18,613,000
Cash flows from investing activities:
Investments in properties	(27,615,000)	(16,530,000)	(17,544,000)
Investments in joint ventures	(21,578,000)	(13,436,000)	(12,315,000)
Return of capital from investments in joint ventures	20,770,000	22,279,000	0
Purchases of investments available for sale	0	0	(24,584,000)
Proceeds from sales of investments available for sale	4,317,000	69,865,000	85,735,000
Cash at consolidation of real estate partnership	0	3,704,000	0
Cash held in escrow	(45,000)	(220,000)	(10,000)
Proceeds from sale of assets	955,000	939,000	19,245,000
Net cash (used in) provided by investing activities	(23,196,000)	66,601,000	50,527,000
Cash flows from financing activities:
Proceeds from long-term debt	0	92,070,000	0
Repayment of long-term debt	0	(90,000,000)	0
Debt issue costs	0	(704,000)	0
Contribution from partner	27,894,000	0	0
Distribution to noncontrolling interest	(11,472,000)	(2,602,000)	(765,000)
Repurchase of company stock	0	(264,000)	(21,312,000)
Exercise of employee stock options	412,000	269,000	239,000
Net cash provided by (used in) financing activities	16,834,000	(1,231,000)	(21,838,000)
Net increase in cash and cash equivalents	15,976,000	87,612,000	47,302,000
Cash and cash equivalents at beginning of year	161,521,000	73,909,000	26,607,000
Cash and cash equivalents at end of the year	177,497,000	161,521,000	73,909,000
Supplemental disclosures of cash flow information:
Interest	2,893,000	2,150,000	960,000
Income taxes	$ (1,761,000)	$ (1,226,000)	$ 2,244,000