CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 186,000	$ 62,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property and equipment	0	285,000
Amortization of operating lease right-of-use asset	9,000	0
Loss from investments in unconsolidated entities, net	233,000	30,000
Accrued interest from notes receivable	0	(2,000)
Accretion of asset retirement obligations	0	7,000
Deferred income taxes	13,000	(244,000)
Changes in:
Accounts receivable	(474,000)	(36,000)
Income taxes receivable/payable	61,000	330,000
Other current assets	(5,000)	(184,000)
Accounts payable and accrued expenses	24,000	(100,000)
Deferred revenue	416,000	511,000
Operating lease right-of-use liability	(9,000)	0
Net cash provided by operating activities	454,000	659,000
Cash flows from investing activities:
Advances made under loans to unconsolidated entities	(430,000)	(820,000)
Principal payments received under sales-type sublease	202,000	0
Net cash used in investing activities	(228,000)	(820,000)
Cash flows from financing activities:
Repayment of finance lease obligations	(318,000)	(257,000)
Net cash used in financing activities	(318,000)	(257,000)
Net change in cash and cash equivalents	(92,000)	(418,000)
Cash and cash equivalents - beginning of year	1,519,000	2,684,000
Cash and cash equivalents - end of year	1,427,000	2,266,000
Cash paid for:
Interest	32,000	35,000
Supplemental disclosure of noncash investing and financing activities:
Recognition of a right-of-use asset	161,000	0
Recognition of a right-of-use liability	176,000	0
Derecognition of deferred rent liability (previously included in accounts payable and accrued expenses)	$ 15,000	$ 0