Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 9,977	$ 10,165
Short-term investments	3,800	2,880
Accounts receivable, net of allowances for doubtful accounts and other adjustments of $450 (2015) and $602 (2014)	7,598	8,216
Income tax receivable	33	706
Inventories, net of reserves for excess and obsolete inventory of $156 (2015) and $151 (2014)	87	97
Prepaid expenses and other current assets	696	765
Total current assets	22,191	22,829
Equipment and improvements, net	3,799	4,273
Other assets	221	214
Deferred tax asset	74	74
Total assets	26,285	27,390
Current liabilities:
Accounts payable	1,660	1,521
Accrued liabilities	5,129	5,752
Deferred revenue	331	1,498
Deferred tax liability	74	74
Total current liabilities	7,194	8,845
Non-current liabilities:
Deferred rent and other long-term liabilities	3,766	3,643
Total non-current liabilities	3,766	3,643
Commitments and contingencies
Stockholders' equity:
Preferred stock, par value $0.001 per share; 5,000,000 shares authorized; none issued or outstanding
Common stock, par value $0.001 per share; 100,000,000 shares authorized; 46,190,276 and 45,000,891 shares issued and outstanding at March 31, 2015 and December 31, 2014, respectively	46	45
Additional paid-in capital	223,572	223,141
Accumulated comprehensive deficit	(208,293)	(208,284)
Total stockholders' equity	15,325	14,902
Total liabilities and stockholders' equity	$ 26,285	$ 27,390