Annual report pursuant to Section 13 and 15(d)

Warrants - Additional Information (Detail)

v3.6.0.2
Warrants - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 21, 2016
Dec. 01, 2016
Sep. 14, 2016
Jun. 30, 2016
May 25, 2016
Mar. 23, 2016
Feb. 21, 2016
Dec. 09, 2015
Nov. 18, 2015
Apr. 01, 2015
Dec. 31, 2016
Dec. 31, 2015
Nov. 12, 2015
Nov. 11, 2015
Dec. 31, 2014
Class of Warrant or Right [Line Items]                              
Warrants exercise price (usd per share)                     $ 4.72        
Warrants to purchase common stock, issued (shares)     137,500           350       75,215    
Shares issuable on exercise of warrants (shares)                       0      
Proceeds from warrants exercised                 $ 1,400   $ 0 $ 1,000      
Warrants issued (shares)                     2,870,000 3,450,000      
Warrant outstanding (shares)                     7,033,000 4,432,000     1,136,000
Class of warrant or right, expired (shares)           70,000 200   14,665 19,138 269,000 154,000      
Exercise price of warrant (usd per share)                 $ 4.00       $ 4.00 $ 10.00  
John Pappajohn                              
Class of Warrant or Right [Line Items]                              
Class of warrant or right, expired (shares) 75,294 37,000   86,533       120,000              
Series B Preferred Stock                              
Class of Warrant or Right [Line Items]                              
Warrant outstanding (shares)                       60,200      
2015 Offering                              
Class of Warrant or Right [Line Items]                              
Warrants to purchase common stock, issued (shares)                         3,000,000    
Exercise price of warrant (usd per share)                         $ 5.00    
Over-Allotment Option                              
Class of Warrant or Right [Line Items]                              
Warrants to purchase common stock, issued (shares)                         450,000    
Private Placement                              
Class of Warrant or Right [Line Items]                              
Warrants to purchase common stock, issued (shares)         1,233,910                    
Warrants, period before exercisable         6 months                    
Warrants, exercise period         5 years                    
Private Placement - September Offering                              
Class of Warrant or Right [Line Items]                              
Warrants to purchase common stock, issued (shares)     1,375,000                        
Warrants, period before exercisable     6 months                        
Warrants, exercise period     5 years                        
Derivative Warrants | Private Placement                              
Class of Warrant or Right [Line Items]                              
Warrants, period before exercisable     6 months                        
Warrants, exercise period     5 years                        
Derivative Warrants | Private Placement | 2016 Offering                              
Class of Warrant or Right [Line Items]                              
Warrants issued (shares)         1,357,301                    
Warrants, period before exercisable         6 months                    
Exercise price of warrant (usd per share)         $ 2.25                    
Warrants, exercise period         5 years                    
Derivative Warrants | Private Placement - September Offering                              
Class of Warrant or Right [Line Items]                              
Warrants issued (shares)     1,512,500                        
Exercise price of warrant (usd per share)     $ 2.25