CONSOLIDATED STATEMENTS OF INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
NET SALES	$ 243,049	$ 221,659	$ 736,930	$ 649,504
COST OF SALES	138,913	119,620	416,194	359,400
GROSS PROFIT	104,136	102,039	320,736	290,104
OPERATING EXPENSES:
Selling, general and administrative	86,936	66,382	245,183	200,389
Research and development	16,987	14,525	49,361	44,163
Intangible asset impairment charge	2,702	657	3,250	657
Contingent consideration expense (benefit)	392	(661)	3,573	(442)
Acquired in-process research and development		75	525	382
Total operating expenses	107,017	80,978	301,892	245,149
INCOME (LOSS) FROM OPERATIONS	(2,881)	21,061	18,844	44,955
OTHER INCOME (EXPENSE):
Interest income	328	359	1,027	847
Interest expense	(3,415)	(2,329)	(9,295)	(8,064)
Other income (expense) - net	278	294	(421)	(429)
Total other expense - net	(2,809)	(1,676)	(8,689)	(7,646)
INCOME (LOSS) BEFORE INCOME TAXES	(5,690)	19,385	10,155	37,309
INCOME TAX EXPENSE (BENEFIT)	(2,292)	2,766	499	4,481
NET INCOME (LOSS)	$ (3,398)	$ 16,619	$ 9,656	$ 32,828
EARNINGS (LOSS) PER COMMON SHARE:
Basic (in dollars per share)	$ (0.06)	$ 0.31	$ 0.18	$ 0.64
Diluted (in dollars per share)	$ (0.06)	$ 0.30	$ 0.17	$ 0.62
AVERAGE COMMON SHARES:
Basic (in shares)	55,152	53,431	55,029	51,434
Diluted (in shares)	55,152	55,103	56,393	53,096