Consolidated Condensed Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Product revenues	$ 213,441	$ 206,182	$ 420,350	$ 400,120
Cost of sales	147,736	145,425	288,075	282,338
Gross margin	65,705	60,757	132,275	117,782
Operating expenses:
Net research and development expenses	14,977	14,550	29,525	27,595
Acquisition transaction expenses				1,075
Selling, general and administrative	24,058	21,693	49,003	39,560
Total operating expenses	39,035	36,243	78,528	68,230
Operating income	26,670	24,514	53,747	49,552
Interest expense	(544)	(970)	(1,108)	(1,901)
Revaluation of derivatives loss	(53)	(340)	(1,017)	(587)
Foreign currency (loss) gain	(107)	(320)	328	(1,843)
Gain from equity investment				785
Other income (expense)	262	41	457	(200)
Earnings before income tax	26,228	22,925	52,407	45,806
Income tax expense	6,734	6,502	13,093	12,804
Net income	$ 19,494	$ 16,423	$ 39,314	$ 33,002
Basic earnings per share	$ 0.54	$ 0.46	$ 1.10	$ 0.94
Diluted earnings per share	$ 0.53	$ 0.46	$ 1.08	$ 0.92
Weighted average number of shares – basic	35,970,992	35,360,957	35,870,649	35,213,135
Weighted average number of shares – diluted	36,584,850	36,093,600	36,428,507	35,841,228