Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 10,863	$ 18,873
Short-term investments	7,196	13,328
Accounts receivable, net of allowances for doubtful accounts and other adjustments of $447 (2013) and $482 (2012)	7,015	8,953
Income tax receivable	680	681
Inventories, net of reserves for excess and obsolete inventory of $357 (2013) and $352 (2012)	162	176
Prepaid expenses and other current assets	1,196	903
Deferred tax asset	89	89
Total current assets	27,201	43,003
Equipment and improvements, net	7,910	11,211
Other assets	223	181
Total assets	35,334	54,395
Current liabilities:
Accounts payable	2,396	1,978
Accrued liabilities	9,850	4,829
Deferred revenue	2,029	1,436
Total current liabilities	14,275	8,243
Non-current liabilities:
Deferred rent and other long-term liabilities	2,051	3,399
Deferred tax liability	91	91
Total non-current liabilities	2,142	3,490
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; 37,033,458 and 35,873,418 shares issued and outstanding at September 30, 2013 and December 31, 2012, respectively	37	36
Additional paid-in capital	213,866	211,165
Accumulated comprehensive deficit	(194,986)	(168,539)
Total stockholders' equity	18,917	42,662
Total liabilities and stockholders' equity	$ 35,334	$ 54,395