Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 29,587	$ 21,856
Short-term investments	27,151	27,188
Accounts receivable, net	15,528	19,725
Inventory	11,836	10,138
Prepaid expenses and other	3,130	3,886
Total current assets	87,232	82,793
Restricted cash	143	143
Deferred offering costs	181	181
Property and equipment, net	10,841	9,414
Other assets	335	338
Total assets	98,732	92,869
Current liabilities:
Accounts payable	3,546	3,243
Accrued liabilities	7,629	12,181
Deferred revenue, current portion	11,749	5,261
Lease financing obligations, current portion	190	226
Total current liabilities	23,114	20,911
Deferred revenue, net of current portion	20,000	6,486
Deferred rent and other long-term liabilities	5,725	4,257
Long-term debt and lease financing obligations, net of current portion and debt issuance costs	41,285	41,000
Total liabilities	$ 90,124	$ 72,654
Commitment and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value, 15,000 shares authorized; none issued	$ 0	$ 0
Common stock, $0.0001 par value, 150,000 shares authorized; 19,772 and 19,570 shares issued and outstanding at March 31, 2016 and December 31, 2015, respectively	2	2
Additional paid-in capital	245,655	242,693
Accumulated other comprehensive income (loss)	5	(29)
Accumulated deficit	(237,054)	(222,451)
Total stockholders’ equity	8,608	20,215
Total liabilities and stockholders’ equity	$ 98,732	$ 92,869