Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 50,527	$ 72,021
Restricted cash	8,500	0
Trade accounts receivable, net	5,886	6,665
Inventory	19,271	9,936
Prepaid expenses and other current assets	6,406	4,257
Total current assets	90,590	92,879
Property and equipment, net	10,615	13,011
Other assets	5,821	6,614
Total assets	107,026	112,504
Current liabilities:
Accounts payable	8,177	4,622
Accrued expenses	12,650	18,865
Accrued compensation	5,206	3,952
Common stock warrant liabilities	4,007	31,341
Deferred revenue	9,303	0
Total current liabilities	39,343	58,780
Notes Payable, Noncurrent	2,375	0
Long-term debt, less current portion	0	28,802
Deferred revenue, less current portion	7,458	0
Other long-term liabilities	315	6,496
Commitments and contingencies
Stockholders' equity:
Common stock	141	139
Additional paid-in capital	438,533	428,534
Accumulated deficit	(381,139)	(410,247)
Total stockholders’ equity	57,535	18,426
Total liabilities and stockholders’ equity	$ 107,026	$ 112,504