CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Revenues	$ 48,647us-gaap_Revenues	$ 49,173us-gaap_Revenues
Cost of revenues	15,335us-gaap_CostOfRevenue	15,433us-gaap_CostOfRevenue
Amortization of acquired intangible assets	369us-gaap_CostOfGoodsSoldAmortization	446us-gaap_CostOfGoodsSoldAmortization
Gross profit	32,943us-gaap_GrossProfit	33,294us-gaap_GrossProfit
Operating expenses:
Research and development	3,851	4,181
Sales and marketing	18,195us-gaap_SellingAndMarketingExpense	18,059us-gaap_SellingAndMarketingExpense
General and administrative	9,138us-gaap_GeneralAndAdministrativeExpense	14,222us-gaap_GeneralAndAdministrativeExpense
Amortization of acquired intangible assets	677us-gaap_AmortizationOfIntangibleAssets	758us-gaap_AmortizationOfIntangibleAssets
Restructuring expenses	(60)us-gaap_RestructuringCharges	776us-gaap_RestructuringCharges
Total operating expenses	31,801us-gaap_OperatingExpenses	37,996us-gaap_OperatingExpenses
Operating income (loss)	1,142us-gaap_OperatingIncomeLoss	(4,702)us-gaap_OperatingIncomeLoss
Other income (expense):
Interest income	7us-gaap_InvestmentIncomeInterest	3us-gaap_InvestmentIncomeInterest
Interest expense	(3,371)us-gaap_InterestExpense	(1,688)us-gaap_InterestExpense
Other income (expense), net	(1,437)us-gaap_OtherNonoperatingIncomeExpense	383us-gaap_OtherNonoperatingIncomeExpense
Total other income (expense)	(4,801)us-gaap_NonoperatingIncomeExpense	(1,302)us-gaap_NonoperatingIncomeExpense
Pretax net loss	(3,659)	(6,004)
Income tax provision	902us-gaap_IncomeTaxExpenseBenefit	669us-gaap_IncomeTaxExpenseBenefit
Net loss	$ (4,561)us-gaap_NetIncomeLoss	$ (6,673)us-gaap_NetIncomeLoss
Net loss per basic and diluted share (in dollars per share)	$ (0.05)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.07)us-gaap_EarningsPerShareBasicAndDiluted
Shares used in calculating basic and diluted net loss per share (in dollars per share)	99,020	96,838

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Name:	us-gaap_AmortizationOfIntangibleAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration