CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Operating activities:
Net income	$ 288,000	$ 275,000	$ 1,439,000	$ 1,261,000	$ 2,940,000
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization			5,138,000	5,050,000
Loss on disposal of assets			0	15,000
Deferred income tax			45,000	500,000
Stock-based compensation expense			169,000	158,000
Net accrued interest on lease financing			39,000	(79,000)
Changes in operating assets and liabilities:
Accounts receivable and other receivables			(398,000)	(1,191,000)
Prepaid expenses and other assets			(473,000)	(944,000)
Deferred revenue			(93,000)	(84,000)
Accounts payable and accrued liabilities			359,000	290,000
Net cash from operating activities			6,225,000	4,976,000
Investing activities:
Payment for purchase of property and equipment			(1,187,000)	(760,000)
Proceeds from sale of equipment			0	150,000
Net cash (used in) investing activities			(1,187,000)	(610,000)
Financing activities:
Principal payments on long-term debt			(1,875,000)	(1,595,000)
Principal payments on capital leases			(3,006,000)	(3,823,000)
Distributions to non-controlling interests			(470,000)	(519,000)
Proceeds from warrants and options exercised			0	115,000
Net cash (used in) financing activities			(5,351,000)	(5,822,000)
Net change in cash, cash equivalents, and restricted cash			(313,000)	(1,456,000)
Cash, cash equivalents, and restricted cash at beginning of period			2,502,000	3,121,000	3,121,000
Cash, cash equivalents, and restricted cash at end of period	$ 2,189,000	$ 1,665,000	2,189,000	1,665,000	$ 2,502,000
Supplemental cash flow disclosure:
Cash paid during the period for: Interest			1,307,000	1,424,000
Cash paid during the period for: Income taxes			354,000	104,000
Schedule of non-cash investing and financing activities
Acquisition of equipment with capital lease financing			1,679,000	2,153,000
Acquisition of equipment with long-term debt financing			$ 0	$ 992,000