Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Income Statement [Abstract]
Net sales	$ 46,256		$ 38,052		$ 141,712		$ 128,897
Cost of sales	24,479		19,511		71,912		69,283
Gross profit	21,777		18,541		69,800		59,614
Operating expenses:
Selling and marketing	14,152		12,434		46,546		41,057
General and administrative	4,907		4,371		13,836		12,672
Research and development	1,382		1,038		3,812		2,957
Total operating expenses	20,441		17,843		64,194		56,686
Operating income	1,336		698		5,606		2,928
Other income (expense):
Interest income	4		3		5		16
Interest expense	(10)		(9)		(25)		66
Other	271		(101)		292		(187)
Total other income (expense)	265		(107)		272		(105)
Income from continuing operations before income taxes	1,601		591		5,878		2,823
Income tax provision (benefit)	101		(625)		(33,814)		(554)
Income from continuing operations	1,500		1,216		39,692		3,377
Discontinued operation:
Loss from discontinued operation before income taxes	(106)		(281)		(367)		(167)
Income tax provision (benefit) of discontinued operation	10		(16)		(81)		(99)
Loss from discontinued operation	(116)		(265)		(286)		(68)
Net income	$ 1,384		$ 951		$ 39,406		$ 3,309
Earnings Per Share, Basic [Abstract]
Basic income per share from continuing operations (in dollars per share)	$ 0.05		$ 0.04		$ 1.28		$ 0.11
Basic loss per share from discontinued operation (in dollars per share)	$ 0.00		$ (0.01)		$ (0.01)		$ 0.00
Basic net income per share (in dollars per share)	$ 0.04	[1]	$ 0.03	[1]	$ 1.27	[1]	$ 0.11	[1]
Earnings Per Share, Diluted [Abstract]
Diluted income per share from continuing operations (in dollars per share)	$ 0.05		$ 0.04		$ 1.26		$ 0.11
Diluted loss per share from discontinued operation (in dollars per share)	$ 0.00		$ (0.01)		$ (0.01)		$ 0.00
Diluted net income per share (in dollars per share)	$ 0.04	[1]	$ 0.03	[1]	$ 1.25	[1]	$ 0.11	[1]
Shares used in per share calculations:
Basic (in shares)	31,128		30,892		31,045		30,892
Diluted (in shares)	31,488		30,943		31,419		31,010

[1] May not add due to rounding