Basis of Presentation - Additional Information (Detail) - USD ($)
 9 Months Ended 12 Months Ended
Aug. 08, 2016
Nov. 07, 2014
Jul. 22, 2014
Feb. 10, 2014
Sep. 30, 2016
Dec. 31, 2016
Dec. 31, 2014
Dec. 31, 2015
Basis Of Presentation [Line Items]                
Proceeds from equity offering, net of expenses $ 9,500,000 $ 34,800,000 $ 11,500,000 $ 4,800,000   $ 9,520,000 $ 51,118,000  
Deemed distribution to preferred shareholders, common stock at fair value           2,184,000    
Working capital           16,000,000    
Cash and cash equivalents, including restricted cash           9,200,000    
Net accounts receivable           $ 9,784,000   $ 8,948,000
Warrants                
Basis Of Presentation [Line Items]                
Number of warrants to purchase aggregate unregistered shares of common stock 2,035,398 9,205,862            
Price per share of unregistered shares of common stock $ 2.00 $ 4.00            
Private Placement                
Basis Of Presentation [Line Items]                
Aggregate unregistered shares 88,494              
Number of warrants to purchase aggregate unregistered shares of common stock 2,035,398 9,205,862            
Price per share of unregistered shares of common stock $ 2.00 $ 4.00            
Conversion of stock, each shares issued 100              
Stock conversion, price $ 1.13              
Conversion of stock, description           On September 30, 2016, the Company held a meeting of its stockholders and received requisite stockholder approval with respect to the issuance of 8,849,400 shares of common stock upon automatic conversion of the Preferred Stock and the issuance of common stock related exercise of the warrants by certain holders whose warrants were subject to a beneficial ownership limitation.    
Conversion of stock, shares issued           8,849,400    
Proceeds from equity offering, gross           $ 10,000,000    
Proceeds from equity offering, net of expenses   $ 34,800,000       9,500,000    
Payments of stock issuance costs   $ 235,000       500,000    
Deemed distribution to preferred shareholders, common stock at fair value           1,100,000    
Private Placement | Convertible Preferred Stock                
Basis Of Presentation [Line Items]                
Proceeds from equity offering, gross           8,900,000    
Private Placement | Warrants                
Basis Of Presentation [Line Items]                
Proceeds from equity offering, gross         $ 1,100,000      
Private Placement | Beneficial Conversion                
Basis Of Presentation [Line Items]                
Proceeds from equity offering, gross           $ 1,100,000    
Private Placement | Common Stock and Warrants                
Basis Of Presentation [Line Items]                
Expected term (years)           5 years    
Risk-free interest rate           1.03%    
Dividend yield           0.00%