CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 15,587	$ 24,508
Short-term investments	98,177	94,506
Accounts receivable, net	17,549	16,656
Inventory, net	12,782	11,222
Prepaid expenses and other current assets	3,278	2,568
Total current assets	147,373	149,460
Property and equipment, net	12,069	11,794
Intangible asset, net	2,229	3,147
Deferred tax asset, net	235	235
Deposits and other assets	1,448	1,200
Total assets	163,354	165,836
Current liabilities:
Accounts payable	4,841	6,244
Accrued liabilities	13,705	20,449
Deferred rent	100	95
Total current liabilities	18,646	26,788
Other liabilities	1,680	846
Total liabilities	20,326	27,634
Commitments and contingencies (Note 9)
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, 34,855 and 34,647 shares issued and 34,827 and 34,619 shares outstanding at March 31, 2018 and December 31, 2017, respectively	35	35
Additional paid-in capital	339,314	331,073
Accumulated other comprehensive loss	(1,295)	(591)
Accumulated deficit	(194,894)	(192,183)
Less treasury stock (28 shares as of March 31, 2018 and December 31, 2017)	(132)	(132)
Total stockholders' equity	143,028	138,202
Total liabilities and stockholders' equity	$ 163,354	$ 165,836