Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Additional Information (Detail)

v2.4.0.8
Common Stock - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock, shares authorized 50,000,000   50,000,000   50,000,000
Common stock, par value $ 0.001   $ 0.001   $ 0.001
Preferred stock, shares authorized 5,000,000   5,000,000    
Preferred stock, par value $ 0.001   $ 0.001    
Common stock, offered and sold 15,577,172   15,577,172   14,707,886
Common stock available for sale under offering $ 22.0   $ 22.0    
Number of Optioned Common Shares, Option exercises     10,000 3,475  
Restricted stock unit settlements     49,348 20,004  
Unrecognized compensation expense related to stock options granted 3.7   3.7   2.7
Effect on diluted per share on shares underlying options, restricted stock units and warrants 3,700,000 3,000,000 3,700,000 3,000,000  
Warrants outstanding 1,587,301   1,587,301    
Exercise price warrants     $ 20    
Warrants expiration date     2015-10    
Number of warrants exercised     0 0  
MLV [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock, offered and sold 809,214   809,214    
Net proceeds from sales of common stock 2.9        
2010 Performance incentive plan [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common shares available for future option grants 929,037   929,037    
Stock options [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Weighted-average period, restricted stock awards     2 years 9 months    
Stock options [Member] | Minimum [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award expiration period     7 years    
Stock options [Member] | Maximum [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award expiration period     10 years    
Stock options [Member] | Employees and consultants [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     4 years    
Stock options [Member] | Board of Directors [Member] | Minimum [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     1 year    
Stock options [Member] | Board of Directors [Member] | Maximum [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     3 years    
Stock options [Member] | 2010 Performance incentive plan [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common shares reserved for issuance under various plans 3,058,616   3,058,616    
Common shares reserved for options currently outstanding 1,258,984   1,258,984    
Restricted stock unit awards [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common shares reserved for awards currently outstanding 870,595   870,595   356,589
Award vesting period     4 years    
Weighted-average period, restricted stock awards     3 years 3 months    
Stock based compensation expense 0.6 0.4 1.1 0.7  
Total unrecognized compensation expense related to the Company's restricted stock unit awards $ 4.2   $ 4.2    
Restricted stock unit awards [Member] | 2010 Performance incentive plan [Member]
         
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common shares reserved for awards currently outstanding 870,595   870,595