Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Consolidated net income (loss)	$ 11,891	$ (1,399)
Adjustments to reconcile consolidated net income (loss) to net cash provided by (used for) operating activities:
Depreciation and amortization	4,539	4,346
Stock-based compensation expense, net	1,916	541
Provision for doubtful accounts	65	8
Decrease in long-term income taxes payable		(7)
Increase in other long-term liabilities	5	87
Decrease in long-term deferred revenue	(36)	(35)
Gain on disposal of equipment	(16)	(23)
Deferred income taxes	25	17
Credit gain on available-for-sale securities	(4)	(6)
Change in current assets and liabilities, net	(9,857)	(4,232)
Net cash provided by (used for) operating activities	8,528	(703)
Investing activities:
Additions to property, plant and equipment	(3,558)	(5,631)
Proceeds from sale of equipment	16	23
Increase in other assets	(67)	(80)
Net cash used for investing activities	(3,609)	(5,688)
Financing activities:
Proceeds from issuance of Common Stock	4,966	1,769
Payment of contingent consideration obligations	(172)	(111)
Net cash provided by financing activities	4,794	1,658
Effect of foreign exchange rates on cash	(23)	(12)
Net increase (decrease) in cash and cash equivalents	9,690	(4,745)
Cash and cash equivalents at beginning of period	44,230	56,170
Cash and cash equivalents at end of period	$ 53,920	$ 51,425