CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
Revenue	$ 155,047	$ 154,029	$ 168,082
Cost of goods sold	55,176	54,464	59,970
Gross profit	99,871	99,565	108,112
Operating costs:
Sales and marketing	40,323	37,768	40,294
Research and development	21,315	18,794	18,636
General and administrative	21,196	20,071	22,450
Amortization of purchased intangible assets	3,325	1,905	1,967
Total operating costs	86,159	78,538	83,347
Operating income	13,712	21,027	24,765
Interest income, net	162	261	543
Other income, net	240	409	500
Income from continuing operations before income taxes	14,114	21,697	25,808
Provision for income taxes	3,147	5,468	1,557
Net income from continuing operations	10,967	16,229	24,251
Net (loss) from discontinued operations	180	(630)	(6,118)
Net income	$ 11,147	$ 15,599	$ 18,133
Basic income (loss) per share:
Continuing operations	$ 0.28	$ 0.43	$ 0.65
Discontinued operations	$ 0.00	$ (0.02)	$ (0.16)
Total net income per share	$ 0.28	$ 0.41	$ 0.48
Diluted income (loss) per share:
Continuing operations	$ 0.28	$ 0.42	$ 0.63
Discontinued operations	$ 0.00	$ (0.02)	$ (0.16)
Total net income per share	$ 0.28	$ 0.40	$ 0.47
Weighted average common shares outstanding:
Basic	38,873	38,068	37,555
Diluted	39,158	38,677	38,568