v2.4.0.8
Stock-Based Compensation - Stock-Based Compensation Included in Unaudited Results of Operations (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock option/warrant expense, included in total operating expenses $ 12 $ 57 $ 104 $ 174
Officer compensation [Member]
        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock option/warrant expense, included in total operating expenses 7 16 38 48
Non-employee directors [Member]
        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock option/warrant expense, included in total operating expenses 2 5 11 15
Sales, general and administrative [Member]
        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock option/warrant expense, included in total operating expenses 3 6 15 21
Research and development [Member]
        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock option/warrant expense, included in total operating expenses   $ 30 $ 40 $ 90