Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 25,322	$ 28,947
Restricted cash, current portion	1,188	901
Short-term investments	157,717	201,586
Accounts receivable, net of allowance of $1,322 in 2016 and $971 in 2015	9,408	5,862
Inventory	9,249	8,093
Prepaid expenses and other current assets	9,394	5,337
Total current assets	212,278	250,726
Property and equipment, net	25,616	12,710
Restricted cash, long term portion	342	683
Other assets	4,149	1,121
Total assets	242,385	265,240
Current liabilities:
Accounts payable	8,811	7,332
Accrued compensation	10,214	8,552
Other accrued liabilities	23,347	18,708
Deferred revenue	576	144
Short-term debt financing	49,473	42,090
Warrants	3,558	3,649
Total current liabilities	95,979	80,475
Deferred rent, net of current portion	6,092
Total liabilities	102,071	80,475
Commitments and contingencies (Note 6)
Stockholders' equity:
Common stock	6	5
Additional paid in capital	447,915	436,259
Accumulated deficit	(307,941)	(250,083)
Accumulated other comprehensive income (loss)	334	(1,416)
Total stockholders' equity	140,314	184,765
Total liabilities and stockholders' equity	$ 242,385	$ 265,240