Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flow from operating activities:
Net loss	$ (1,956,000)	$ (1,908,000)
Adjustments to reconcile net loss to net cash provided by operating activities:
Equity-based compensation	924,000	583,000
Depreciation	569,000	535,000
Noncash lease expense	108,000	100,000
Amortization of premium of marketable securities	105,000	37,000
Provision for bad debt	121,000
Equity loss in investee	249,000	279,000
Other	(42,000)	(28,000)
Changes in operating assets and liabilities:
Accounts receivable	104,000	1,414,000
Other current and long-term assets	(924,000)	64,000
Accounts payable	1,907,000	79,000
Income tax payable	34,000
Accrued liabilities and other current liabilities	268,000	(7,000)
Operating lease liabilities	(101,000)	(93,000)
Net cash provided by operating activities	1,366,000	1,055,000
Cash flow from investing activities:
Purchases of fixed assets	(796,000)	(134,000)
Purchase of marketable securities	(7,992,000)	(5,988,000)
Maturities of marketable securities	4,926,000	3,600,000
Net cash used in investing activities	(3,862,000)	(2,522,000)
Cash flow from financing activities:
Proceeds from exercise of stock options	12,000	4,000
Payment of public offering costs	(130,000)
Repurchases of capital stock	(46,000)
Net cash (used in) provided by financing activities	(164,000)	4,000
Effect of exchange rate changes on cash and cash equivalents	(3,000)	15,000
Net decrease in cash and cash equivalents	(2,663,000)	(1,448,000)
Cash and cash equivalents at beginning of period	11,965,000	6,736,000
Cash and cash equivalents at end of period	9,302,000	5,288,000
Supplemental disclosures of non-cash investing and financing activities:
Fixed assets included in accounts payable	43,000	$ 45,000
Purchase of marketable securities in other current liabilities	500,000
Public offerings costs included in accounts payable	$ 1,000