CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
NET SALES	$ 138,077	$ 129,577
COST OF SALES	77,977	74,194
GROSS PROFIT	60,100	55,383
OPERATING EXPENSES:
Selling, general and administrative	41,704	36,885
Research and development	10,588	9,672
Contingent consideration expense	102	122
Total operating expenses	52,394	46,679
INCOME FROM OPERATIONS	7,706	8,704
OTHER INCOME (EXPENSE):
Interest income	9	53
Interest expense	(1,329)	(1,574)
Other income (expense) — net	(480)	280
Other expense — net	(1,800)	(1,241)
INCOME BEFORE INCOME TAXES	5,906	7,463
INCOME TAX EXPENSE	1,555	2,289
NET INCOME	$ 4,351	$ 5,174
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 0.10	$ 0.12
Diluted (in dollars per share)	$ 0.10	$ 0.12
AVERAGE COMMON SHARES:
Basic (in shares)	44,275	43,703
Diluted (in shares)	44,579	44,145