Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 22,943	$ 17,177	$ 10,590
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,324	4,055	3,591
Stock-based compensation	2,349	2,256	1,680
Fair value adjustments to contingent consideration obligations	(29)	106
Provision for doubtful accounts and allowances	264	230	105
Provision for inventory write-downs	671	396	362
Provision (benefit) for deferred income taxes	(2,152)	300	140
Gain on acquisitions and divestitures	(7,474)
Foreign currency transaction gain	259	(29)	59
Changes in operating assets and liabilities:
Accounts receivable	(1,283)	(1,507)	(922)
Inventory and other deferred costs	(4,262)	(1,352)	(134)
Prepaid expenses and other assets	(418)	(288)	1,528
Accounts payable and other liabilities	4,314	1,524	(103)
Net cash provided by operating activities	19,506	22,868	16,896
Investing activities
Purchases of property and equipment	(3,054)	(6,417)	(2,841)
Payments related to acquisitions	(12,282)		(14,368)
Purchases of short-term marketable securities	(19,619)	(22,541)
Proceeds from sales of marketable securities	20,500
Proceeds from divestitures	7,400
Purchase of intellectual property			(2)
Net cash used in investing activities	(7,055)	(28,958)	(17,211)
Financing activities
Payment of deferred acquisition consideration	(1,199)	(463)	(385)
Proceeds from issuance of common stock	2,969	5,500	1,442
Purchase of treasury stock	(741)	(778)	(311)
Common stock cash dividend paid	(5,445)	(4,179)	(3,323)
Net cash provided by (used in) financing activities	(4,416)	80	(2,577)
Effect of exchange rate changes on cash and cash equivalents	(813)	818	(271)
Net increase (decrease) in cash and cash equivalents	7,222	(5,192)	(3,163)
Cash and cash equivalents at beginning of year	19,096	24,288	27,451
Cash and cash equivalents at end of year	$ 26,318	$ 19,096	$ 24,288