CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
NET SALES	$ 136,086	$ 128,808	$ 403,745	$ 376,909
COST OF SALES	76,881	71,387	228,271	211,821
GROSS PROFIT	59,205	57,421	175,474	165,088
OPERATING EXPENSES:
Selling, general, and administrative	39,201	36,328	115,407	111,682
Research and development	10,515	8,688	29,389	27,109
Intangible asset impairment charges	0	1,102	0	1,102
Contingent consideration (benefit) expense	(58)	(773)	185	(754)
Acquired in-process research and development	1,000	0	1,000	0
Total operating expenses	50,658	45,345	145,981	139,139
INCOME FROM OPERATIONS	8,547	12,076	29,493	25,949
OTHER INCOME (EXPENSE):
Interest income	78	41	210	187
Interest expense	(1,489)	(2,008)	(4,776)	(6,967)
Other income (expense) — net	(476)	144	(281)	52
Other (expense) — net	(1,887)	(1,823)	(4,847)	(6,728)
INCOME BEFORE INCOME TAXES	6,660	10,253	24,646	19,221
INCOME TAX EXPENSE	1,842	2,489	7,253	4,918
NET INCOME	$ 4,818	$ 7,764	$ 17,393	$ 14,303
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 0.11	$ 0.18	$ 0.40	$ 0.33
Diluted (in dollars per share)	$ 0.11	$ 0.18	$ 0.39	$ 0.33
AVERAGE COMMON SHARES:
Basic (in shares)	44,165	43,229	43,976	43,053
Diluted (in shares)	44,734	43,398	44,467	43,315