CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 9,345	$ 8,170	$ 16,093
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,594	4,020	3,114
Stock-based compensation expense	3,598	1,766	1,060
Deferred tax expense (benefit)	(118)	295	2,788
Loss on revaluation of contingent consideration	4,083	2,072	91
Loss on disposal of assets	1	35	2
Changes in assets and liabilities:
Accounts receivable	(3,729)	(1,597)	(774)
Royalties and other receivables	158	6,557	2,400
Inventories	(6,149)	(860)	(626)
Prepaid expenses and other current assets	(277)	(820)	58
Accounts payable	3,024	2,288	(734)
Accrued liabilities	(1,592)	(2,489)	1,257
Long-term liabilities	2,115	(1,036)	1,201
Net cash provided by operating activities	15,053	18,401	25,930
Cash flows from investing activities:
Purchases of marketable securities	(20,168)	(27,508)	(42,480)
Redemptions of marketable securities	27,587	34,804	29,209
Acquisition of assets of Refine Technology, LLC		(21,236)
Increase of restricted cash		(250)
Purchases of property, plant and equipment	(2,628)	(5,602)	(4,635)
Net cash provided by (used in) investing activities	4,791	(19,792)	(17,906)
Cash flows from financing activities:
Exercise of stock options	866	1,680	2,450
Excess tax benefit on exercise of stock options			72
Payments of contingent consideration	(99)
Net cash provided by financing activities	767	1,680	2,522
Effect of exchange rate changes on cash and cash equivalents	(1,882)	(4,756)	74
Net increase (decrease) in cash and cash equivalents	18,729	(4,467)	10,620
Cash and cash equivalents, beginning of period	35,363	39,830	29,210
Cash and cash equivalents, end of period	54,092	35,363	39,830
Supplemental information:
Income taxes paid	$ 4,948	$ 2,547	$ 1,264