CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Net sales	$ 60,772	$ 61,200	$ 109,891	$ 107,996
Cost of sales (excluding amortization, shown separately below)	11,620	8,905	21,365	48,558
Gross profit	49,152	52,295	88,526	59,438
Research and development expenses	3,071	2,983	10,103	11,220
Selling, general, and administrative expenses	14,462	15,173	44,328	49,385
Amortization of intangibles	10,445	10,080	31,335	29,878
Change in fair value of contingent consideration	(1,424)	(1,569)	(2,420)	(4,969)
Operating income (loss)	22,598	25,628	5,180	(26,076)
Other (expense) income	(295)	(38)	(40)	16
(Loss) gain on foreign currency exchange	(487)	924	10,584	682
Interest expense, net	(8,638)	(14,526)	(27,495)	(43,850)
Income (loss) before income taxes	13,178	11,988	(11,771)	(69,228)
Income tax expense (benefit)	3,632	4,676	(11,895)	(26,239)
Net income (loss)	$ 9,546	$ 7,312	$ 124	$ (42,989)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.19	$ 0.15	$ 0.00	$ (0.87)
Diluted (in dollars per share)	$ 0.19	$ 0.15	$ 0.00	$ (0.87)
Weighted average shares outstanding:
Basic (in shares)	49,676,923	49,567,735	49,852,337	49,385,733
Diluted (in shares)	50,169,434	49,627,800	50,134,591	49,385,733