CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 15,500	$ 19,285
Short-term investments	37,307	38,831
Accounts receivable, net	20,016	22,244
Inventory	53,278	47,083
Prepaid expenses and other current assets	1,533	2,359
Total current assets	127,634	129,802
Property and equipment, net	16,918	18,110
Other non-current assets	214	241
Goodwill and other intangible assets, net	3,881	3,881
Total assets	148,647	152,034
Current liabilities:
Accounts payable	5,299	4,666
Accrued compensation and employee related benefits	5,992	5,729
Accrued liabilities	3,140	3,162
Accrued restructuring costs	1,590
Current portion of long-term debt	1,593	4,088
Current portion of capital lease obligations	703	936
Current portion of deferred rent	374	628
Current portion of deferred revenue	509	714
Total current liabilities	19,200	19,923
Long-term debt, net of current portion	18,266	5,500
Capital lease obligations, net of current portion	495	745
Long-term liabilities — other	560	532
Long-term restructuring liabilities	685
Deferred rent, net of current portion	5,495	5,891
Deferred revenue, net of current portion	219	501
Total liabilities	44,920	33,092
Stockholders' equity:
Preferred stock, $0.001 par value — 5,000 shares authorized, no shares issued and outstanding at June 30, 2018 and December 31, 2017
Common stock, $0.001 par value — 495,000 shares authorized, 21,395 and 20,973 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	21	21
Additional paid-in capital	330,441	323,482
Accumulated other comprehensive loss	(36)	(36)
Accumulated deficit	(226,699)	(204,525)
Total stockholders' equity	103,727	118,942
Total liabilities and stockholders' equity	$ 148,647	$ 152,034