Consolidated Condensed Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Product revenues	$ 235,853	$ 232,625	$ 728,498	$ 681,059
Cost of sales	165,624	155,931	494,704	464,628
Gross margin	70,229	76,694	233,794	216,431
Operating expenses:
Net research and development expenses	19,721	19,745	60,633	54,552
Acquisition transaction expenses		22		693
Selling, general and administrative expenses	34,331	29,512	96,912	81,533
Total operating expenses	54,052	49,279	157,545	136,778
Operating income	16,177	27,415	76,249	79,653
Interest expense	(1,250)	(660)	(3,633)	(2,287)
Foreign currency (loss) gain	(7,340)	(873)	(21,920)	88
Other (expense) income	(403)	359	6	754
Earnings before income tax	7,184	26,241	50,702	78,208
Income tax expense	630	6,018	10,233	27,646
Net income	$ 6,554	$ 20,223	$ 40,469	$ 50,562
Basic earnings per share	$ 0.18	$ 0.55	$ 1.10	$ 1.39
Diluted earnings per share	$ 0.18	$ 0.55	$ 1.10	$ 1.38
Weighted average number of shares – basic	36,742,168	36,477,044	36,713,294	36,425,626
Weighted average number of shares – diluted	36,805,076	36,594,581	36,831,213	36,558,363