Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 40,775	$ 10,006
Restricted cash		9,139
Short-term investments	12,684
Accounts receivable	2,050	2,970
Inventories	10,754	4,872
Prepaid expenses and other current assets	2,357	478
Total current assets	68,620	27,465
Property, plant and equipment, net	5,726	3,528
Other assets	1,057	2,785
Total assets	75,403	33,778
Current liabilities:
Accounts payable	5,125	2,104
Accrued liabilities	2,973	3,023
Deferred revenue, current portion	1,094	324
Capital lease obligations, current portion	782	207
Debt, current portion	177	8,572
Convertible notes payable, current portion		22,518
Total current liabilities	10,151	38,933
Deferred revenue, less current portion	1,453	1,696
Capital lease obligations, less current portion	538	195
Debt, less current portion	12,261	7,766
Convertible notes payable, less current portion		19,342
Other liabilities	569	481
Total liabilities	24,972	68,413
Commitments and contingencies (Note 13)
Preferred stock
Stockholders' deficit:
Common stock: $0.00001 par value; 250,000 shares authorized and 19,199 shares issued and outstanding at September 30, 2013; 12,936 shares authorized and 1,267 shares issued and outstanding at December 31, 2012
Additional paid-in capital	145,876	1,322
Accumulated deficit	(95,445)	(75,569)
Total stockholders' equity (deficit)	50,431	(74,247)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	75,403	33,778
Convertible preferred stock - Series A [Member]
Current liabilities:
Preferred stock		3,747
Convertible preferred stock - Series B [Member]
Current liabilities:
Preferred stock		10,758
Convertible preferred stock - Series C [Member]
Current liabilities:
Preferred stock		25,107
Preferred stock [Member]
Current liabilities:
Warrant liability		1,884
Common stock [Member]
Current liabilities:
Warrant liability		$ 301