Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 13,462	$ 9,803
Marketable investments	62,595	71,343
Accounts receivable, net	10,400	11,137
Inventories	11,855	10,988
Deferred tax asset	26	26
Other current assets and prepaid expenses	1,699	1,591
Total current assets	100,037	104,888
Property and equipment, net	1,545	1,461
Deferred tax asset, net of current portion	291	269
Intangibles, net	450	595
Goodwill	1,339	1,339
Other long-term assets	362	361
Total assets	104,024	108,913
Current liabilities:
Accounts payable	2,855	3,083
Accrued liabilities	8,946	11,007
Deferred revenue	8,971	8,898
Total current liabilities	20,772	22,988
Deferred revenue, net of current portion	3,714	4,346
Income tax liability	167	145
Other long-term liabilities	798	926
Total liabilities	25,451	28,405
Commitments and Contingencies (Note 10)
Stockholders’ equity:
Common stock, $0.001 par value; authorized: 50,000,000 shares; issued and outstanding: 14,715,896 and 14,446,950 shares at March 31, 2015 and December 31, 2014, respectively	15	14
Additional paid-in capital	107,408	105,721
Accumulated deficit	(28,876)	(25,232)
Accumulated other comprehensive income	26	5
Total stockholders’ equity	78,573	80,508
Total liabilities and stockholders’ equity	104,024	108,913
Convertible Preferred Stock [Member]
Stockholders’ equity:
Convertible preferred stock, $0.001 par value; authorized: 5,000,000 shares; none issued and outstanding	$ 0	$ 0