Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 24,039	$ 20,459
Securities available-for-sale	6,413	9,788
Accounts receivable, net	6,320	7,527
Inventories, net	6,178	5,432
Other current assets	855	861
Restricted cash	194	0
Total current assets	43,999	44,067
Property and equipment, net	5,367	7,185
Intangible assets, net	477	808
Goodwill	184	184
Total assets	50,027	52,244
Liabilities and stockholders' equity
Accounts payable	1,330	1,694
Accrued compensation	2,291	1,600
Accrued warranty	297	378
Deferred revenue	2,099	2,379
Other accrued liabilities	2,397	2,096
Total current liabilities	8,414	8,147
Deferred rent	126	138
Total liabilities	8,540	8,285
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, $0.0001 par value: 10,000,000 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.0001 par value: 80,000,000 shares authorized; 18,901,160 and 18,597,311 shares issued and outstanding (net of treasury shares) at December 31, 2011 and 2010, respectively	2	2
Treasury stock, at cost; 582,825 shares and 573,218 shares at December 31, 2011 and 2010, respectively	(1,058)	(1,039)
Additional paid-in capital	155,704	154,785
Accumulated other comprehensive income	33	63
Accumulated deficit	(113,194)	(109,852)
Total stockholders' equity	41,487	43,959
Total liabilities and stockholders' equity	$ 50,027	$ 52,244