Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Consolidated net income	$ 14,109	$ 31,846	$ 258
Adjustments to reconcile consolidated net income to net cash provided by (used for) operating activities:
Depreciation and amortization	10,334	9,254	8,893
Stock-based compensation expense	3,036	3,396	1,735
Increase (decrease) in long-term income taxes payable	329	43	(1)
Deferred income taxes	60	(55)	(172)
Increase (decrease) in long-term deferred revenue	822	(71)	(71)
Increase in other long-term liabilities		9	93
Gain on disposal of equipment	(38)	(57)	(14)
(Benefit) provision for doubtful accounts	(144)	65	6
Credit gain on available-for-sale securities	(4)	(7)	(11)
Increase in refundable income taxes			(736)
Increase in contingent consideration obligations	280		650
Change in current assets and liabilities, net	(6,576)	(8,252)	(13,094)
Net cash provided by (used for) operating activities	22,208	36,171	(2,464)
Investing activities:
Additions to property, plant and equipment	(12,485)	(18,211)	(12,545)
Proceeds from sale of equipment	38	57	14
(Decrease) increase in other assets	(35)	(85)	5
Net cash used for investing activities	(12,482)	(18,239)	(12,526)
Financing activities:
Proceeds from issuance of Common Stock	4,742	8,656	3,300
Payment of contingent consideration obligations	(237)	(270)	(225)
Noncontrolling interest dividend paid	(139)
Net cash provided by financing activities	4,366	8,386	3,075
Effect of foreign exchange rates on cash	19	9	(25)
Net increase (decrease) in cash and cash equivalents	14,111	26,327	(11,940)
Cash and cash equivalents at beginning of year	70,557	44,230	56,170
Cash and cash equivalents at end of year	84,668	70,557	44,230
Change in current assets and liabilities, excluding effects of deconsolidation of subsidiary:
Accounts receivable	5,714	(8,834)	(9,210)
Inventories, net	(1,812)	(10,827)	(9,309)
Other current assets	(2,895)	176	(357)
Accounts payable and accrued liabilities	(7,339)	7,450	3,186
Accrued severance and other charges	(234)	234
Short-term lease payable	12
Income taxes payable	(653)	410	208
Deferred revenue	631	3,139	2,388
Change in current assets and liabilities, net	(6,576)	(8,252)	(13,094)
Supplemental disclosures:
Cash paid during the year for income taxes, net of refunds	$ 2,194	$ 743	$ 373