Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities
Net income	$ 50	$ 1,878
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Inventories allowances	49	64
Deferred tax expense	100	610
Depreciation and amortization	471	456
Share-based and stock compensation expense	16	26
Restricted stock unit compensation expense	6	0
Realized tax benefit from stock option exercise	0	380
Gain on available-for-sale securities	(617)	0
Loss on disposal of property, plant and equipment	104	0
Changes in operating assets and liabilities:
Trade accounts receivable	(1,865)	(1,794)
Inventories	(843)	320
Prepaid expenses and other current assets	527	1,175
Other assets	(25)	17
Accounts payable	899	2,275
Accrued compensation and related taxes	(838)	676
Accrued warranty expense	410	(20)
Deferred revenue	(6)	(16)
Customer deposits	0	989
Accrued other expenses and other current liabilities	203	66
Net cash (used in) provided by operating activities	(1,359)	7,102
Investing activities
Purchases of property, plant and equipment	(447)	(962)
Investment in securities	0	(481)
Proceeds from sale of available-for-sale securities	897	0
Net cash used in investing activities	450	(1,443)
Financing activities
Proceeds from issuance of common stock	183	10
Cash dividends declared and paid	(2,477)	(1,236)
Repurchase of common stock	(217)	(22)
Cash provided by financing activities	(2,511)	(1,248)
Net change in cash and cash equivalents	(3,420)	4,411
Cash and cash equivalents, beginning of period	10,910	4,669
Cash and cash equivalents, end of period	7,490	9,080
Supplemental disclosure
Cash paid for interest	0	0
Income tax paid	0	0
Non-cash financing activity
Cashless exercise of stock options and related conversion of net shares to stockholders' equity	$ 27	$ 4