Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Net sales	$ 71,903	$ 59,214
Cost of sales	33,422	28,520
Gross profit	38,481	30,694
Operating expenses:
Selling and marketing	21,774	18,626
General and administrative	5,803	4,947
Research and development	1,903	1,127
Total operating expenses	29,480	24,700
Operating income	9,001	5,994
Other income (expense):
Interest income	8	1
Interest expense	(7)	(9)
Other	(61)	(109)
Total other income (expense)	(60)	(117)
Income from continuing operations before income taxes	8,941	5,877
Income tax provision	3,193	353
Income from continuing operations	5,748	5,524
Discontinued operations:
Loss from discontinued operations before income taxes	(512)	(374)
Income tax benefit from discontinued operations	(138)	(9)
Loss from discontinued operations	(374)	(365)
Net income	$ 5,374	$ 5,159
Earnings Per Share, Basic [Abstract]
Basic income per share from continuing operations (in dollars per share)	$ 0.18	$ 0.18
Basic loss per share from discontinued operation (in dollars per share)	$ (0.01)	$ (0.01)
Basic net income per share (in dollars per share)	$ 0.17	$ 0.17
Earnings Per Share, Diluted [Abstract]
Diluted income per share from continuing operations (in dollars per share)	$ 0.18	$ 0.18
Diluted loss per share from discontinued operation (in dollars per share)	$ (0.01)	$ (0.01)
Diluted net income per share (in dollars per share)	$ 0.17	$ 0.17
Shares used in per share calculations:
Basic (in shares)	31,172	30,947
Diluted (in shares)	31,550	31,264