Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 48,921	$ 41,135
Marketable securities	262,179	265,744
Accounts receivable, net	8,526	4,933
Inventory, net	6,833	6,677
Prepaid expenses and other current assets	7,114	7,375
Total current assets	333,573	325,864
Property and Equipment, at cost:
Computer equipment and computer software	20,767	14,025
Laboratory equipment	14,749	12,786
Leasehold improvements	13,549	7,118
Assets under construction	6,711	8,038
Buildings	4,792	4,777
Furniture and fixtures	2,515	1,265
Property and Equipment, gross	63,083	48,009
Less-Accumulated depreciation	(24,941)	(13,913)
Net property and equipment	38,142	34,096
Other long-term assets	5,325	4,070
Total assets	377,040	364,030
Current Liabilities:
Accounts payable	710	3,308
Accrued liabilities	28,106	22,253
Debt and capital lease obligation, current portion	174	166
Other short-term liabilities	1,702	996
Total current liabilities	30,692	26,723
Long-term debt	4,633	4,789
Other long-term liabilities	5,734	4,601
Lease incentive obligation, less current portion	686	1,061
Total liabilities	41,745	37,174
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $0.01 par value Authorized—5,000,000 shares issued and outstanding—no shares at December 31, 2016 and 2015
Common stock, $0.01 par value Authorized—200,000,000 shares issued and outstanding—110,236,127 and 96,674,786 shares at December 31, 2016 and 2015	1,102	967
Additional paid-in capital	1,080,432	904,932
Accumulated other comprehensive loss	(418)	(433)
Accumulated deficit	(745,821)	(578,610)
Total stockholders' equity	335,295	326,856
Total liabilities and stockholders’ equity	$ 377,040	$ 364,030