Non-Recurring Fair Value Measurements - Additional Information (Detail) - USD ($)
1 Months Ended 12 Months Ended
Dec. 03, 2014
Jul. 09, 2014
Jul. 20, 2012
Mar. 31, 2015
Dec. 31, 2015
Dec. 31, 2014
Dec. 08, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]              
Class of Warrants or right to purchase common stock 44,531 6,566 161,977 7,398 156,138 156,138 44,531
Class of Warrants or right to purchase common stock, exercise price       $ 9.75 $ 0.01 $ 0.01  
Warrants expiry period     10 years 10 years      
Fair value of the warrants, risk free interest rate     0.22%        
Fair value of the warrants, implied volatility     99.00%        
Fair value of the warrants, expected term to liquidity     1 year 8 months 12 days        
Fair value of warrants     $ 117,000        
Surrender of warrant to satisfy other liability 5,839            
Warrants outstanding         156,138    
Silicon Valley Bank [Member]              
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]              
Class of Warrants or right to purchase common stock         6,566    
Class of Warrants or right to purchase common stock, exercise price         $ 7.99    
Warrants expiry period         10 years    
Fair value of the warrants, risk free interest rate   2.58%          
Fair value of the warrants, implied volatility   87.00%          
Fair value of the warrants, expected term to liquidity   10 years          
Fair value of warrants   $ 51,000          
Amount of loan to purchase equipment   $ 1,750,000          
Amount of loan, interest rate stated percentage           6.00%  
Bank loan and security agreement, repayment period   36 months          
Warrants outstanding         6,566    
Silicon Valley Bank [Member] | Prime Rate [Member]              
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]              
Amount of loan bears interest basis spread on variable rate   2.75%          
Series A Preferred Stock [Member]              
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]              
Class of Warrants or right to purchase common stock     161,977        
Class of Warrants or right to purchase common stock, exercise price     $ 0.01