STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating Activities:
Net income (loss)	$ (5,021,000)	$ 1,399,000
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	1,647,000	1,167,000
Imapirment loss	2,014,000	0
Changes in allowance for doubtful accounts	43,000	(191,000)
Deferred income tax expense	(504,000)	259,000
Stock-based compensation	422,000	410,000
Gain on sale of property and equipment	0	(35,000)
Changes in operating assets and liabilities:
Accounts receivable	1,161,000	3,292,000
Inventories	31,000	(52,000)
Income tax receivable	1,000	233,000
Prepaid expenses and other	(69,000)	109,000
Accounts payable	(224,000)	95,000
Accrued liabilities	(1,680,000)	463,000
Accrued income taxes	30,000	32,000
Deferred revenue	(162,000)	(70,000)
Net cash provided by operating activities	(2,311,000)	7,111,000
Investing Activities:
Purchases of property and equipment	(398,000)	(1,337,000)
Proceeds from sale of property and equipment	0	35,000
Purchase of held to maturity investments	(4,981,000)	0
Proceeds from sale of held to maturity investments	4,981,000	0
Net cash used in investing activities	(398,000)	(1,302,000)
Financing Activities:
Cash dividends paid ($0.70 per share)	(14,000)	(14,000)
Proceeds from issuance of common stock, net	108,000	49,000
Repurchase of common stock upon vesting of restricted stock awards and vesting of restricted stock units	(35,000)	(81,000)
Repurchase of common stock, net	0	(298,000)
Net cash used in financing activities	59,000	(344,000)
Increase (decrease) in cash and cash equivalents	(2,650,000)	5,465,000
Cash and cash equivalents at beginning of year	10,160,000	4,695,000
Cash and cash equivalents at end of year	7,510,000	10,160,000
Supplemental disclosures for cash flow information:
Cash paid (refunded) during the year for income taxes	8,000	(39,000)
Non-cash investing and financing activities:
Cash dividends declared included in accounts payable	28,000	42,000
Purchases of property and equipment included in accounts payable and accrued liabilities	$ 0	$ 60,000