Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Consolidated Statements of Operations
Net sales	$ 146,344	$ 98,637	$ 280,059	$ 203,139
Cost of sales	86,178	56,743	164,978	114,826
Gross profit	60,166	41,894	115,081	88,313
Operating expenses, net:
Research and development	22,553	19,254	44,398	38,449
Selling, general, and administrative	21,466	17,818	41,722	36,123
Amortization of intangible assets	2,976	3,834	6,330	7,671
Restructuring		472		1,097
Asset impairment		281		281
Other operating expense (income), net	(81)	(174)	(36)	(283)
Total operating expenses, net	46,914	41,485	92,414	83,338
Operating income (loss)	13,252	409	22,667	4,975
Interest income	235	427	370	1,227
Interest expense	(6,820)	(6,041)	(13,578)	(11,706)
Loss on extinguishment of debt		(3,046)		(3,046)
Income (loss) before income taxes	6,667	(8,251)	9,459	(8,550)
Income tax expense (benefit)	319	51	617	319
Net income (loss)	$ 6,348	$ (8,302)	$ 8,842	$ (8,869)
Income (loss) per common share:
Basic (in dollars per share)	$ 0.13	$ (0.17)	$ 0.18	$ (0.18)
Diluted (in dollars per share)	$ 0.12	$ (0.17)	$ 0.17	$ (0.18)
Weighted average number of shares:
Basic (in shares)	48,743	48,109	48,758	48,147
Diluted (in shares)	53,942	48,109	53,539	48,147