Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 12,306	$ 12,620
Restricted cash, current portion	5,612	59
Short-term investments	70,901	106,247
Accounts receivable, net of allowance of $1,773 in 2018 and $2,000 in 2017	57,002	44,089
Inventory	12,324	8,998
Prepaid expenses and other current assets	7,225	8,612
Total current assets	165,370	180,625
Property and equipment, net	25,313	29,667
Restricted cash, long term portion	342	342
Other assets	3,336	3,979
Total assets	194,361	214,613
Current liabilities:
Accounts payable	7,689	8,529
Accrued compensation	8,615	9,599
Other accrued liabilities	30,520	33,257
Deferred revenue, current portion	1,174	1,420
Short-term debt financing	50,132	50,112
Warrants		2,644
Total current liabilities	98,130	105,561
Long-term debt financing	73,211	73,065
Deferred rent, net of current portion	8,922	9,241
Deferred revenue, long-term portion	36,135
Other long-term liabilities		1,329
Total liabilities	216,398	189,196
Commitments and contingencies (Note 7)
Stockholders' equity (deficit):
Common stock, $0.0001 par value: 750,000 shares authorized at both June 30, 2018 and December 31, 2017, respectively; 55,454 and 54,040 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	6	6
Additional paid in capital	491,887	472,552
Accumulated deficit	(513,072)	(446,375)
Accumulated other comprehensive loss	(858)	(766)
Total stockholders' (deficit) equity	(22,037)	25,417
Total liabilities and stockholders' equity (deficit)	$ 194,361	$ 214,613