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 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total stock option/warrant expense, included in total operating expenses $ 20 $ 35 $ 41 $ 92
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 9 15 18 31
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 4 4 9 9
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 7 6 14 12
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   $ 10   $ 40