Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 21,199	$ 26,136
Short-term investments	73,731	51,419
Accounts receivable, net	18,530	19,564
Inventory, net	15,018	20,057
Prepaid expenses and other	7,057	4,745
Total current assets	135,535	121,921
Restricted cash	0	143
Property and equipment, net	15,191	14,057
Other assets	636	641
Total assets	151,362	136,762
Current liabilities:
Accounts payable	5,618	4,092
Accrued liabilities	2,937	4,507
Accrued compensation and other employee benefits	9,122	8,634
Customer deposits	10,208	8,945
Deferred revenue, current portion	8,905	9,229
Deferred rent, current portion	617	512
Total current liabilities	37,407	35,919
Deferred revenue, net of current portion	3,594	3,304
Deferred rent and other long-term liabilities	8,143	8,499
Long-term debt, net of debt issuance costs	50,133	48,931
Total liabilities	99,277	96,653
Commitment and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value, 15,000 shares authorized; none issued	0	0
Common stock, $0.0001 par value, 150,000 shares authorized; 30,769 and 25,421 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	3	2
Additional paid-in capital	422,282	353,308
Accumulated other comprehensive loss	(54)	(99)
Accumulated deficit	(370,146)	(313,102)
Total stockholders’ equity	52,085	40,109
Total liabilities and stockholders’ equity	$ 151,362	$ 136,762