CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 10,503	$ 5,640
Short-term investments	10,382	14,598
Accounts receivable, net	798	729
Inventories	1,468	1,597
Prepaid expenses and other	903	701
Total current assets	24,054	23,265
Property and equipment, net	1,567	1,630
Goodwill	23,134	23,134
Other assets	746	663
Total assets	49,501	48,692
Current liabilities
Accounts payable	358	940
Accrued expenses and other	2,225	2,664
Total current liabilities	2,583	3,604
Convertible notes payable	7,879
Other long-term liabilities	245	247
Total liabilities	$ 10,707	$ 3,851
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; 65,975 shares and 65,496 shares issued and outstanding at March 31, 2016 and December 31, 2015, respectively	$ 660	$ 655
Additional paid-in capital	226,971	226,174
Accumulated other comprehensive loss		(16)
Accumulated deficit	(188,837)	(181,972)
Total stockholders' equity	38,794	44,841
Total liabilities and stockholders' equity	$ 49,501	$ 48,692

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).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.