Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ 864	$ (4,744)	$ 2,117
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	2,194	2,041	1,755
Stock-based compensation	844	685	579
Loss on impairment of assets of discontinued operations		796
Loss on sale of discontinued operations	164
Change in deferred gain		(55)	(110)
Loss on disposition of property	9	55
Change in allowance for doubtful accounts	162	35	15
Equity in loss of investments	421	78	208
Amortization of debt issuance costs	80	57
Changes in operating assets and liabilities:
Accounts receivable	(2,040)	1,493	(842)
Inventories	(3,114)	1,813	(4,329)
Other assets	(811)	(741)	(13)
Accounts payable	3,729	(1,386)	1,588
Accrued expenses	1,622	(545)	(118)
Other liabilities	106	13	(186)
Net cash provided by (used in) operating activities	4,230	(405)	664
Cash flows from investing activities:
Proceeds from sale of property, plant and equipment	19
Investment in partnerships	(1,776)
Purchases of property, plant and equipment	(2,313)	(1,766)	(3,982)
Net cash used in investing activities	(4,720)	(2,302)	(4,179)
Cash flows from financing activities:
Proceeds from long-term borrowings	19,162	19,357	19,615
Repayments of long-term borrowings	(19,373)	(19,524)	(16,284)
Payment of debt issuance costs	(139)	(140)
Proceeds from equity offering, net of offering costs		3,678
Proceeds from employee stock purchases and exercise of stock options	314	137	340
Change in restricted cash	(67)	23	60
Net cash (used in) provided by financing activities	(103)	3,531	3,731
Effect of exchange rate changes on cash	299	(524)	(177)
Net increase in cash	(294)	300	39
Cash, beginning of year	667	367	328
Cash, beginning of year	373	667	367
PC Werth Ltd [Member]
Cash flows from investing activities:
Purchase of businesses, net of cash received (Note 4)			$ (197)
Hearing Help Express (HHE) [Member]
Cash flows from investing activities:
Purchase of businesses, net of cash received (Note 4)	$ (650)	$ (536)