Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Net sales	$ 48,546	$ 36,242	$ 120,450	$ 95,456
Cost of sales	23,766	18,913	57,189	47,433
Gross profit	24,780	17,329	63,261	48,023
Operating expenses:
Selling and marketing	15,690	13,768	37,463	32,394
General and administrative	4,959	3,982	10,762	8,929
Research and development	1,752	1,303	3,655	2,430
Total operating expenses	22,401	19,053	51,880	43,753
Operating income (loss)	2,379	(1,724)	11,381	4,270
Other income (expense):
Interest income	16	0	24	1
Interest expense	(5)	(6)	(12)	(15)
Other, net	(56)	130	(117)	21
Total other income (expense)	(45)	124	(105)	7
Income (loss) from continuing operations before income taxes	2,334	(1,600)	11,276	4,277
Income tax provision (benefit)	836	(34,268)	4,030	(33,915)
Income from continuing operations	1,498	32,668	7,246	38,192
Discontinued operations:
Income (loss) from discontinued operations before income taxes	(322)	113	(834)	(261)
Income tax provision (benefit) from discontinued operations	619	(82)	481	(91)
Income (loss) from discontinued operations	(941)	195	(1,315)	(170)
Net income	$ 557	$ 32,863	$ 5,931	$ 38,022
Earnings Per Share, Basic [Abstract]
Basic income per share from continuing operations (in dollars per share)	$ 0.05	$ 1.05	$ 0.23	$ 1.23
Basic loss per share from discontinued operation (in dollars per share)	$ (0.03)	$ 0.01	$ (0.04)	$ (0.01)
Basic net income per share (in dollars per share)	$ 0.02	$ 1.06	$ 0.19	$ 1.23
Earnings Per Share, Diluted [Abstract]
Diluted income per share from continuing operations (in dollars per share)	$ 0.05	$ 1.04	$ 0.23	$ 1.22
Diluted loss per share from discontinued operation (in dollars per share)	$ (0.03)	$ 0.01	$ (0.04)	$ (0.01)
Diluted net income per share (in dollars per share)	$ 0.02	$ 1.05	$ 0.19	$ 1.21
Shares used in per share calculations:
Basic (in shares)	31,226	31,058	31,203	31,003
Diluted (in shares)	31,598	31,430	31,586	31,360