Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	[1]
Income Statement [Abstract]
Net sales	$ 84,400	$ 114,813
Cost of sales	48,558	55,942
Gross profit	35,842	58,871
Operating expenses:
Selling and marketing	34,043	36,763
General and administrative	7,655	6,910
Research and development	4,311	4,501
Total operating expenses	46,009	48,174
Operating (loss) income	(10,167)	10,697
Other income (expense):
Interest income	165	272
Interest expense	(205)	(293)
Other, net	(393)	(13)
Total other expense, net	(433)	(34)
(Loss) income from continuing operations before income taxes	(10,600)	10,663
Income tax (benefit) expense	(2,116)	2,523
(Loss) income from continuing operations	(8,484)	8,140
Discontinued operations:
Loss from discontinued operations before income taxes	(14)	(17)
Income tax expense of discontinued operations	77	64
Loss from discontinued operations	(91)	(81)
Net (loss) income	$ (8,575)	$ 8,059	[2]
Earnings Per Share, Basic [Abstract]
Basic income per share from continuing operations (in dollars per share)	$ (0.29)	$ 0.27
Basic loss per share from discontinued operation (in dollars per share)	0	0
Basic net income per share (in dollars per share)	(0.29)	0.27
Earnings Per Share, Diluted [Abstract]
Diluted income per share from continuing operations (in dollars per share)	(0.29)	0.27
Diluted loss per share from discontinued operation (in dollars per share)	0	0
Diluted net income per share (in dollars per share)	$ (0.29)	$ 0.26
Shares used in per share calculations:
Basic (in shares)	29,573	30,314
Diluted (in shares)	29,573	30,591

[1] May not add due to rounding.

[2]