Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 599,691	$ 122,420
Short-term investments	479,369	195,425
Accounts receivable	29,468	5,228
Inventory	83,605	12,813
Restricted investment		10,695
Other current assets	36,511	26,895
Total Current Assets	1,228,644	373,476
Property and equipment, net of accumulated depreciation of $18,022 and $30,346 as of December 31, 2017 and 2016, respectively	43,156	37,801
Intangible assets, net of accumulated amortization of $4,145 and $3,134 as of December 31, 2017 and 2016, respectively	14,355	8,076
Investments and other assets	21,809	4,751
Total Assets	1,307,964	424,104
Current Liabilities:
Accounts payable	8,467	29,690
Accrued expenses	68,982	31,016
Current portion of long-term debt	6,175	10,108
Deferred revenue	3,316	3,303
Other current liabilities	1,392	1,305
Total Current Liabilities	88,332	75,422
Long-term debt	424,876	6,042
Deferred rent and other	5,539	5,949
Total Liabilities	518,747	87,413
Commitments and contingencies (Note 19)
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; 64,791,670 and 54,759,234 issued and outstanding at December 31, 2017 and 2016, respectively	6	5
Additional paid-in capital	2,006,598	1,503,126
Accumulated other comprehensive loss	(379)	(120)
Accumulated deficit	(1,217,008)	(1,166,320)
Total Stockholders’ Equity	789,217	336,691
Total Liabilities and Stockholders’ Equity	$ 1,307,964	$ 424,104