Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Common stock	APIC	Accumulated Deficit	Total
Balance at Dec. 31, 2014	$ 8	$ 460,179	$ (210,989)	$ 249,198us-gaap_StockholdersEquity
Balance (in shares) at Dec. 31, 2014	79,811,769			79,811,769us-gaap_CommonStockSharesOutstanding
Increase (Decrease) in Stockholders' Equity
Net loss			(11,623)	(11,623)us-gaap_NetIncomeLoss
Stock-based compensation		9,784		9,784
Issuance of warrants and change in fair value of unvested warrants relating to marketing agreements		(147)		(147)
Net exercise of warrants to purchase common stock (in shares)	959,676
Shares issued in connection with employee stock plans, net of shares withheld for employee taxes		3,531		3,531
Shares issued in connection with employee stock plans, net of shares withheld for employee taxes (in shares)	889,473
Balance at Mar. 31, 2015	$ 8	$ 473,347	$ (222,612)	$ 250,743us-gaap_StockholdersEquity
Balance (in shares) at Mar. 31, 2015	81,660,918			81,660,918us-gaap_CommonStockSharesOutstanding

This element represents the amount of recognized equity-based compensation during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized). Alternate captions include the words "stock-based compensation".

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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- Definition

Value of stock (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of stock value of such awards forfeited. Stock issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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