CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
NET SALES	$ 542,149	$ 509,689	$ 449,049
COST OF SALES	306,368	284,467	254,682
GROSS PROFIT	235,781	225,222	194,367
OPERATING EXPENSES:
Selling, general and administrative	156,348	147,894	128,642
Research and development	40,810	36,632	33,886
Intangible asset impairment charges	0	1,102	8,089
Contingent consideration expense (benefit)	80	(572)	(4,094)
Acquired in-process research and development	1,000	0	0
Total operating expenses	198,238	185,056	166,523
INCOME FROM OPERATIONS	37,543	40,166	27,844
OTHER INCOME (EXPENSE):
Interest income	272	217	255
Interest expense	(6,229)	(8,829)	(8,044)
Other income (expense) — net	(386)	18	(216)
Other expense — net	(6,343)	(8,594)	(8,005)
INCOME BEFORE INCOME TAXES	31,200	31,572	19,839
INCOME TAX EXPENSE	7,398	8,598	3,269
NET INCOME	$ 23,802	$ 22,974	$ 16,570
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 0.54	$ 0.53	$ 0.39
Diluted (in dollars per share)	$ 0.53	$ 0.53	$ 0.39
AVERAGE COMMON SHARES:
Basic (in shares)	44,036	43,143	42,607
Diluted (in shares)	44,511	43,409	42,884