Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 11,209	$ 7,888
Accounts receivable, net of allowances of $38 and $38, respectively	996	1,687
Inventory	906	862
Other current assets	590	638
Total current assets	13,701	11,075
Property and equipment, net	1,537	1,669
Restricted cash	435	435
Intangible assets	813	845
Other assets	18	18
Total assets	16,504	14,042
Current liabilities
Accounts payable	2,354	2,183
Accrued liabilities	3,882	3,399
Deferred revenue	1,203	2,122
Total current liabilities	7,439	7,704
Deferred revenue, net of current portion	5,903	6,149
Deferred rent, net of current portion	304	342
Total liabilities	$ 13,646	14,195
Commitments and contingencies (Note 6)
Shareholders' equity
Preferred stock, par value $0.001; 25,000 shares authorized; 0 and 0 shares issued and outstanding	$ 0	0
Common stock, par value $0.001; 100,000 shares authorized; 51,494 and 47,423 shares issued and outstanding	51	47
Additional paid-in capital	489,734	483,171
Accumulated deficit	(486,927)	(483,371)
Total shareholders' equity (deficit)	2,858	(153)
Total liabilities and shareholders' equity (Deficit)	$ 16,504	$ 14,042

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).

Name:	us-gaap_AccountsPayableCurrent
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.