CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 39,534	$ 29,821
Short-term investments	113,385	110,667
Accounts receivable, net	24,345	18,673
Inventory, net	12,801	13,282
Prepaid expenses and other current assets	19,223	4,124
Total current assets	209,288	176,567
Restricted cash	8,881	8,775
Property and equipment, net	20,038	19,153
Operating lease right-of-use asset	12,146
Finance lease right-of-use asset	53,343
Income tax receivable	213	213
Deposits and other assets	3,527	2,262
Total assets	307,436	206,970
Current liabilities:
Accounts payable	3,501	6,286
Accrued liabilities	29,602	23,964
Deferred rent		115
Total current liabilities	33,103	30,365
Operating lease liability	11,406
Finance lease liability	68,851
Other liabilities	3,960	2,745
Total liabilities	117,320	33,110
Commitments and contingencies (Note 10)
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000 shares authorized; no shares issued and outstanding
Common stock, $0.001 par value; 150,000 shares authorized; 36,945 and 36,135 shares issued and 36,917 and 36,107 shares outstanding as of September 30, 2019 and December 31, 2018, respectively	37	36
Additional paid-in capital	414,665	378,352
Accumulated other comprehensive income	1,837	738
Accumulated deficit	(226,291)	(205,134)
Less treasury stock (28 shares as of September 30, 2019 and December 31, 2018)	(132)	(132)
Total stockholders' equity	190,116	173,860
Total liabilities and stockholders' equity	$ 307,436	$ 206,970