CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
NET SALES	$ 151,071	$ 138,082	$ 289,148	$ 267,659
COST OF SALES	84,217	77,196	162,193	151,390
GROSS PROFIT	66,854	60,886	126,955	116,269
OPERATING EXPENSES:
Selling, general and administrative	43,653	39,321	85,358	76,206
Research and development	11,529	9,202	22,116	18,874
Contingent consideration expense	91	121	193	243
Total operating expenses	55,273	48,644	107,667	95,323
INCOME FROM OPERATIONS	11,581	12,242	19,288	20,946
OTHER INCOME (EXPENSE):
Interest income	16	79	25	132
Interest expense	(1,768)	(1,713)	(3,097)	(3,287)
Other income (expense) — net	33	(85)	(447)	195
Other expense — net	(1,719)	(1,719)	(3,519)	(2,960)
INCOME BEFORE INCOME TAXES	9,862	10,523	15,769	17,986
INCOME TAX EXPENSE	2,572	3,122	4,128	5,411
NET INCOME	$ 7,290	$ 7,401	$ 11,641	$ 12,575
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 0.16	$ 0.17	$ 0.26	$ 0.29
Diluted (in dollars per share)	$ 0.16	$ 0.17	$ 0.26	$ 0.28
AVERAGE COMMON SHARES:
Basic (in shares)	44,308	44,055	44,297	43,880
Diluted (in shares)	44,703	44,517	44,647	44,332