Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 122,420	$ 80,304
Short-term investments	195,425	112,187
Accounts receivable	5,228	3,977
Inventory	12,813
Restricted investment	10,695	10,695
Other current assets	26,895	17,380
Total Current Assets	373,476	224,543
Restricted cash and investments	784	783
Property and equipment, net of accumulated depreciation of $30,346 and $24,594 as of December 31, 2016 and 2015, respectively	37,801	37,344
Intangible assets, net of accumulated amortization of $3,134 and $2,620 as of December 31, 2016 and 2015, respectively	8,076	6,642
Other assets	3,967	4,470
Total Assets	424,104	273,782
Current Liabilities:
Accounts payable	29,690	20,234
Accrued expenses	31,016	29,053
Current portion of long-term debt	10,108	5,936
Current portion of notes payable		2,493
Deferred revenue	3,303	3,303
Other current liabilities	1,305	1,275
Total Current Liabilities	75,422	62,294
Long-term debt	6,042	14,969
Deferred rent and other	5,949	6,172
Total Liabilities	87,413	83,435
Commitments and contingencies (Note 16)
Stockholders’ Equity:
Preferred stock, $.0001 par value, 3,333,333 shares authorized; none issued and outstanding
Common stock, $.0001 par value, 99,000,000 shares authorized; 54,759,234 and 45,629,529 issued and outstanding at December 31, 2016 and 2015, respectively	5	5
Additional paid-in capital	1,503,126	1,089,508
Accumulated other comprehensive loss	(120)	(111)
Accumulated deficit	(1,166,320)	(899,055)
Total Stockholders’ Equity	336,691	190,347
Total Liabilities and Stockholders’ Equity	$ 424,104	$ 273,782