Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 406,562	$ 459,955	$ 453,042
Cost of sales	101,889	100,607	96,628
Gross profit	304,673	359,348	356,414
Sales and marketing	204,434	223,676	205,527
General and administrative	67,948	85,607	83,251
Research and development	39,056	34,637	33,218
Acquisition-related amortization and remeasurement	(499)	34,212	4,324
Operating income (loss)	(6,266)	(18,784)	30,094
Interest expense, net	(2,483)	(122)	(828)
Other income (expense), net	8,381	(8,143)	(6,381)
Income (loss) before income taxes	(368)	(27,049)	22,885
Income tax benefit (expense)	2,885	(1,413)	(9,074)
Net income (loss)	$ 2,517	$ (28,462)	$ 13,811
Net income (loss) per common share:
Basic	$ 0.13	$ (1.51)	$ 0.73
Diluted	$ 0.13	$ (1.51)	$ 0.72
Weighted average number of common shares:
Basic	19,267,920	18,903,289	18,494,002
Diluted	19,391,718	18,903,289	18,911,610
Other comprehensive income (loss), before tax
Unrealized gain (loss) on debt securities	$ 1,881	$ (2,593)	$ 1,770
Reclassification adjustment for amortization of historical unrealized gains on debt security		(1,034)
Reclassification adjustment for loss on debt security in net income		(5,193)
Currency translation adjustment	4,872	(653)	(1,823)
Other comprehensive income (loss), before tax	6,753	(9,473)	(53)
Income tax benefit (expense) related to items of other comprehensive income (loss)	(462)	2,201	(438)
Other comprehensive income (loss), net of tax	6,291	(7,272)	(491)
Comprehensive income (loss)	$ 8,808	$ (35,734)	$ 13,320