CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
NET SALES	$ 138,082	$ 128,865	$ 267,659	$ 248,101
COST OF SALES	77,196	73,241	151,390	140,434
GROSS PROFIT	60,886	55,624	116,269	107,667
OPERATING EXPENSES:
Selling, general, and administrative	39,321	38,591	76,206	75,354
Research and development	9,202	9,641	18,874	18,421
Contingent consideration expense	121	8	243	19
Total operating expenses	48,644	48,240	95,323	93,794
INCOME FROM OPERATIONS	12,242	7,384	20,946	13,873
OTHER INCOME (EXPENSE):
Interest income	79	79	132	146
Interest expense	(1,713)	(2,353)	(3,287)	(4,959)
Other income (expense) — net	(85)	(28)	195	(92)
Other (expense) — net	(1,719)	(2,302)	(2,960)	(4,905)
INCOME BEFORE INCOME TAXES	10,523	5,082	17,986	8,968
INCOME TAX EXPENSE	3,122	1,366	5,411	2,429
NET INCOME	$ 7,401	$ 3,716	$ 12,575	$ 6,539
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 0.17	$ 0.09	$ 0.29	$ 0.15
Diluted (in dollars per share)	$ 0.17	$ 0.09	$ 0.28	$ 0.15
AVERAGE COMMON SHARES:
Basic (in shares)	44,055	43,061	43,880	42,963
Diluted (in shares)	44,517	43,310	44,332	43,272