Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities:
Consolidated net income (loss)	$ 31,846	$ 258	$ (6,261)
Adjustments to reconcile consolidated net income (loss) to net cash provided by (used for) operating activities:
Depreciation and amortization	9,254	8,893	8,438
Stock-based compensation expense	3,396	1,735	506
Increase (decrease) in long-term income taxes payable	43	(1)	4
Deferred income taxes	(55)	(172)	(78)
Decrease in long-term deferred revenue	(71)	(71)	(94)
Increase in other long-term liabilities	9	93
(Gain) loss on disposal of equipment	(57)	(14)	4
Provision (benefit) for doubtful accounts	65	6	(22)
Credit gain on available-for-sale securities	(7)	(11)	(13)
Increase in refundable income taxes		(736)
Increase in contingent consideration obligations		650
Increase in other assets			(505)
Change in current assets and liabilities, net	(8,252)	(13,094)	(1,435)
Net cash provided by (used for) operating activities	36,171	(2,464)	544
Investing activities:
Additions to property, plant and equipment	(18,211)	(12,545)	(8,428)
Proceeds from sale of equipment	57	14	2
(Decrease) increase in other assets	(85)	5	(93)
Net cash used for investing activities	(18,239)	(12,526)	(8,519)
Financing activities:
Proceeds from issuance of Common Stock	8,656	3,300	1,584
Payment of contingent consideration obligations	(270)	(225)	(99)
Deconsolidation of subsidiary			(372)
Net cash provided by financing activities	8,386	3,075	1,113
Effect of foreign exchange rates on cash	9	(25)	52
Net increase (decrease) in cash and cash equivalents	26,327	(11,940)	(6,810)
Cash and cash equivalents at beginning of year	44,230	56,170	62,980
Cash and cash equivalents at end of year	70,557	44,230	56,170
Change in current assets and liabilities, excluding effects of deconsolidation of subsidiary:
Accounts receivable	(8,834)	(9,210)	780
Inventories, net	(10,827)	(9,309)	(3,677)
Other current assets	176	(357)	(158)
Accounts payable and accrued liabilities	7,450	3,186	339
Accrued severance and other charges	234		(195)
Income taxes payable	410	208	61
Deferred revenue	3,139	2,388	1,415
Change in current assets and liabilities, net	(8,252)	(13,094)	(1,435)
Supplemental disclosures:
Cash paid during the year for income taxes, net of refunds	$ 743	$ 373	$ 230