Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) Share data in Millions, unless otherwise specified	12 Months Ended					12 Months Ended			12 Months Ended
	Dec. 31, 2012 Customer	Dec. 31, 2011 Customer	Dec. 31, 2010	Aug. 31, 2009 2009 Unit Offering Warrant	Nov. 30, 2010 2010 Unit Offering Warrant	Dec. 31, 2012 Maximum	Dec. 31, 2012 Minimum	Dec. 31, 2011 Minimum	Dec. 31, 2012 Minimum Available-for-sale Securities
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue	$ 77,000	$ 111,000
Highly liquid investments, original maturities						3 months
Short-term investments, original maturities						1 year	3 months		1 year
Number of major customers representing outstanding trade receivables	3	2
Cumulative outstanding trade receivables percentage by major customers	59.00%	58.00%					10.00%	10.00%
Life of inventory	2 years
Protracted length of inventory	P1Y
Inventory valuation reserves	300,000	600,000
Unsalable product having offsetting warranty claim	1,700,000	0
Estimated useful life of property and equipment						5 years	3 years
Estimated useful life of intangible assets	10 years
Impairment charges on long-lived assets	0	0	0
Foreign currency gains (losses)	86,000	(529,000)	(816,000)
Warrants to purchase an aggregate shares of common stock				2.4	3.7
Derecognition of tax positions, Maximum						50.00%
Company's tax years subject to examination by the taxing jurisdictions						2012	1998
Unrecognized Tax Benefits	0	0
Period of warranty	1 year
Warrants obligation provided	900,000
Product warranty receivable current	$ 1,800,000