Condensed Consolidated Statements of Cash Flows - Unaudited - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES
Net income	$ 6,051	$ 1,143
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	309	315
Amortization of finite-lived intangible assets	56	56
Recovery of note receivable		(4)
Stock-based compensation	17	19
Unrealized gain on marketable securities	(179)	(183)
Deferred income tax (benefit) expense	(3,306)	28
Changes in operating assets and liabilities:
Increase in accounts receivable, net	(1,508)	(712)
Increase in inventories, net	(2,010)	(542)
(Increase) decrease in prepaid expenses and other assets	(110)	21
Increase in accounts payable, accrued compensation and commissions and other accrued liabilities	1,769	548
Net cash provided by operating activities	1,089	689
INVESTING ACTIVITIES
Purchase of marketable securities, net	(5,000)	(12,275)
Capital expenditures	(826)	(232)
Net cash used in investing activities	(5,826)	(12,507)
FINANCING ACTIVITIES
Proceeds from warrant exercise		927
Proceeds from stock option exercise	390	27
Net cash provided by financing activities	390	954
Decrease in cash and cash equivalents	(4,347)	(10,864)
Cash and cash equivalents at beginning of period	15,508	13,250
Cash and cash equivalents at end of period	11,161	2,386
Supplemental Disclosure:
Cash paid for interest	6	23
Cash paid for income taxes	72	$ 45
Non-Cash Disclosure:
Right-of-use assets offset by operating lease liabilities	$ 364