Condensed Consolidated Statements of Cash Flows - Unaudited - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
OPERATING ACTIVITIES
Net income	$ 582	$ 193
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	101	104
Amortization of finite-lived intangible assets	18	18
Recovery of note receivable		(4)
Stock-based compensation	6	7
Gain on marketable securities	(77)	(12)
Deferred income tax expense	13	(7)
Changes in operating assets and liabilities:
Increase in accounts receivable, net	(1,005)	(259)
Increase in inventories, net	(707)	(133)
(Increase) decrease in prepaid expenses and other assets	(52)	72
Increase in accounts payable, accrued compensation and commissions and other accrued liabilities	1,243	179
Net cash provided by operating activities	122	158
INVESTING ACTIVITIES
Purchase of marketable securities, net	(5,000)
Capital expenditures	(403)	(172)
Net cash used in investing activities	(5,403)	(172)
FINANCING ACTIVITIES
Proceeds from stock option exercise	71	22
Net cash provided by financing activities	71	22
(Decrease) increase in cash and cash equivalents	(5,210)	8
Cash and cash equivalents at beginning of period	15,508	13,250
Cash and cash equivalents at end of period	10,298	13,258
Supplemental Disclosure:
Cash paid for interest	6	11
Cash paid for income taxes	$ 10	$ 9