Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Net sales		$ 70,690	$ 59,067	$ 226,624	$ 179,517
Cost of sales		34,481	30,272	105,870	87,461
Gross profit		36,209	28,795	120,754	92,056
Operating expenses:
Selling and marketing		21,742	17,086	70,193	54,549
General and administrative		5,505	5,745	15,376	16,507
Research and development		2,573	1,683	7,259	5,338
Total operating expenses		29,820	24,514	92,828	76,394
Operating income		6,389	4,281	27,926	15,662
Other income (expense):
Interest income		61	18	164	42
Interest expense		(6)	(9)	(17)	(21)
Other, net		(15)	43	(412)	(74)
Total other income (expense), net		40	52	(265)	(53)
Income from continuing operations before income taxes		6,429	4,333	27,661	15,609
Income tax provision		2,556	1,669	10,710	5,699
Income from continuing operations		3,873	2,664	16,951	9,910
Discontinued operations:
Loss from discontinued operations before income taxes		(159)	(241)	(472)	(1,075)
Income tax provision (benefit) from discontinued operations		(14)	(64)	(405)	417
Loss from discontinued operations		(145)	(177)	(67)	(1,492)
Net income		$ 3,728	$ 2,487	$ 16,884	$ 8,418
Earnings Per Share, Basic [Abstract]
Basic income per share from continuing operations (in dollars per share)		$ 0.12	$ 0.09	$ 0.54	$ 0.32
Basic loss per share from discontinued operation (in dollars per share)		0.00	(0.01)	0.00	(0.05)
Basic net income per share (in dollars per share)		0.12	0.08	0.54	0.27
Earnings Per Share, Diluted [Abstract]
Diluted income per share from continuing operations (in dollars per share)		0.12	0.08	0.53	0.31
Diluted loss per share from discontinued operation (in dollars per share)		0.00	(0.01)	0.00	(0.05)
Diluted net income per share (in dollars per share)	[1]	$ 0.12	$ 0.08	$ 0.53	$ 0.27
Shares used in per share calculations:
Basic (in shares)		31,272	31,287	31,386	31,231
Diluted (in shares)		31,527	31,655	31,702	31,641

[1] May not add due to rounding.