CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
NET SALES	$ 238,349	$ 203,035
COST OF SALES	133,713	114,979
GROSS PROFIT	104,636	88,056
OPERATING EXPENSES:
Selling, general and administrative	78,270	64,913
Research and development	16,043	14,322
Contingent consideration expense	775	40
Acquired in-process research and development	25	0
Total operating expenses	95,113	79,275
INCOME FROM OPERATIONS	9,523	8,781
OTHER INCOME (EXPENSE):
Interest income	357	146
Interest expense	(2,764)	(2,398)
Other expense - net	(270)	(170)
Total other expense — net	(2,677)	(2,422)
INCOME BEFORE INCOME TAXES	6,846	6,359
INCOME TAX EXPENSE	651	1,090
NET INCOME	$ 6,195	$ 5,269
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 0.11	$ 0.10
Diluted (in dollars per share)	$ 0.11	$ 0.10
AVERAGE COMMON SHARES:
Basic (in shares)	54,917	50,277
Diluted (in shares)	56,490	51,910