CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 7,020	$ 3,110
Short-term investments	26,066us-gaap_ShortTermInvestments	20,439us-gaap_ShortTermInvestments
Accounts receivable, net	82us-gaap_AccountsReceivableNetCurrent	177us-gaap_AccountsReceivableNetCurrent
Inventories	1,177us-gaap_InventoryNet	881us-gaap_InventoryNet
Prepaid expenses and other	1,020	887
Total current assets	35,365us-gaap_AssetsCurrent	25,494us-gaap_AssetsCurrent
Long-term investments	7,597us-gaap_LongTermInvestments	2,245us-gaap_LongTermInvestments
Property and equipment, net	830us-gaap_PropertyPlantAndEquipmentNet	854us-gaap_PropertyPlantAndEquipmentNet
Goodwill	23,134us-gaap_Goodwill	23,134us-gaap_Goodwill
Other assets	631us-gaap_OtherAssetsNoncurrent	899us-gaap_OtherAssetsNoncurrent
Total assets	67,557us-gaap_Assets	52,626us-gaap_Assets
Current liabilities
Accounts payable	311us-gaap_AccountsPayableCurrent	495us-gaap_AccountsPayableCurrent
Accrued expenses and other	2,287us-gaap_AccruedLiabilitiesCurrent	2,350us-gaap_AccruedLiabilitiesCurrent
Total current liabilities	2,598us-gaap_LiabilitiesCurrent	2,845us-gaap_LiabilitiesCurrent
Long-term liabilities	245us-gaap_LiabilitiesNoncurrent	241us-gaap_LiabilitiesNoncurrent
Commitments and contingencies (Note 4)
Stockholders' equity
Preferred stock, $0.01 par value; 20,000 shares authorized; none issued and outstanding
Common stock, $0.01 par value; 120,000 shares authorized; 64,639 shares and 49,793 shares issued and outstanding at March 31, 2015 and December 31, 2014, respectively	646us-gaap_CommonStockValue	498us-gaap_CommonStockValue
Additional paid-in capital	222,526	199,541
Accumulated other comprehensive loss	(4)	(10)
Accumulated deficit	(158,454)	(150,489)
Total stockholders' equity	64,714us-gaap_StockholdersEquity	49,540us-gaap_StockholdersEquity
Total liabilities and stockholders' equity	$ 67,557	$ 52,626

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Subparagraph a

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(a))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682