Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 29,928	$ 46,407
Restricted cash	55	4,597
Short-term investments	208,053	107,461
Accounts receivable, net of allowance of $1,997 in 2019 and $1,788 in 2018	62,974	62,223
Inventory	15,236	13,633
Prepaid expenses and other current assets	5,721	6,197
Total current assets	321,967	240,518
Property and equipment, net	22,039	24,336
Operating lease right-of-use assets	26,229
Other assets	13,091	3,317
Total assets	383,326	268,171
Current liabilities:
Accounts payable	8,319	14,587
Accrued compensation	10,149	12,668
Other accrued liabilities	39,157	32,442
Deferred revenue, current portion	19,154	4,131
Short-term debt financing	50,146	50,153
Total current liabilities	126,925	113,981
Long-term debt financing	73,511	73,357
Deferred rent, net of current portion		8,613
Deferred revenue, long-term portion	60,527	40,058
Operating lease liabilities, long-term portion	29,275
Total liabilities	290,238	236,009
Commitments and contingencies (Note 8)
Stockholders' equity:
Common stock, $0.0001 par value: 750,000 shares authorized at both June 30, 2019 and December 31, 2018, respectively; 70,035 and 62,083 shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively	7	7
Additional paid in capital	733,137	607,236
Accumulated deficit	(640,851)	(574,529)
Accumulated other comprehensive income (loss)	795	(552)
Total stockholders' equity	93,088	32,162
Total liabilities and stockholders' equity	$ 383,326	$ 268,171