Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenues	$ 339,410	$ 347,337	$ 343,374
Cost of goods sold	200,649	172,526	168,489
Gross profit	138,761	174,811	174,885
Operating expenses
Sales and marketing	40,901	41,888	43,159
General and administrative	69,270	61,244	50,167
Research and development	32,788	20,018	17,071
Total operating expenses	142,959	123,150	110,397
Operating (loss) income	(4,198)	51,661	64,488
Interest expense	9,479	13,617	17,405
Loss on extinguishment of debt	0	3,196	0
Other (income) loss	(2,198)	6,221	(2,465)
(Loss) income before income taxes	(11,479)	28,627	49,548
Income tax expense (benefit)	1,994	(3,040)	9,030
Net (loss) income	$ (13,473)	$ 31,667	$ 40,518
Net (loss) income per common share:
Basic (in dollars per share)	$ (0.25)	$ 0.81	$ 1.06
Diluted (in dollars per share)	$ (0.25)	$ 0.79	$ 1.03
Weighted-average common shares outstanding:
Basic (in shares)	54,134	38,988	38,233
Diluted (in shares)	54,134	40,113	39,501