Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 54,977	$ 30,818
Marketable securities	112,544	118,187
Accounts receivable, net-includes related party receivables of $6.9 million and $2.2 million as of December 31, 2013 and 2012, respectively	10,452	3,280
Unbilled revenues	1,101	3,150
Inventories	9,836	6,890
Prepaid expenses and other current assets	2,907	2,954
Total current assets	191,817	165,279
Property, plant and equipment, net	40,089	32,225
Investments in unconsolidated joint ventures	22,532	19,047
Other assets	4,267	473
Total assets	258,705	217,024
Current liabilities:
Accounts payable	7,949	7,552
Accrued liabilities	15,005	9,320
Current portion of long-term debt	65	7,331
Deferred revenue	2,275	292
Other current liabilities		443
Total current liabilities	25,294	24,938
Warrant liability	688	835
Long-term debt	10,374	7,637
Convertible debt, inclusive of derivative liability of $5,914 and net of unamortized debt discount of $4,610 as of December 31, 2013	83,083
Other liabilities	318	303
Total liabilities	119,757	33,713
Commitments and contingencies (Note 12)
Stockholders' equity:
Preferred stock, par value $0.001-5,000,000 shares authorized at December 31, 2013 and 2012; 0 shares issued and outstanding at December 31, 2013 and 2012
Common stock, par value $0.001-150,000,000 shares authorized at December 31, 2013 and 2012; 68,744,534 and 61,000,724 shares issued and outstanding at December 31, 2013 and 2012, respectively	69	61
Additional paid-in capital	448,990	373,577
Accumulated other comprehensive loss	(3,794)	(399)
Accumulated deficit	(306,317)	(189,928)
Total stockholders' equity	138,948	183,311
Total liabilities and stockholders' equity	$ 258,705	$ 217,024