Annual report pursuant to Section 13 and 15(d)

Stock Compensation Plan - Summary of Stock Option Activity (Detail)

v3.8.0.1
Stock Compensation Plan - Summary of Stock Option Activity (Detail) - $ / shares
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of Options, Outstanding, beginning balance 162,153 147,105
Number of Options, Forfeited (7,120) (57,477)
Number of Options, Granted 105,600 72,525
Number of Options, Outstanding, ending balance 260,633 162,153
Number of Options, Exercisable 105,821  
Option Price Per Share, granted $ 3.70  
Weighted Average Exercise Price, Outstanding, beginning balance 12.80 $ 20.00
Weighted Average Exercise Price, Forfeited 16.50 24.00
Weighted Average Exercise Price, Granted 3.70 6.90
Weighted Average Exercise Price, Outstanding, ending balance 9.00 12.80
Weighted Average Exercise Price, Exercisable 12.10  
Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Option Price Per Share, beginning balance 5.50 7.80
Option Price Per Share, forfeited 6.20 8.40
Option Price Per Share, granted   5.50
Option Price Per Share, ending balance 3.70 5.50
Option Price Per Share, exercisable 5.50  
Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Option Price Per Share, beginning balance 104.00 104.00
Option Price Per Share, forfeited 54.00 54.00
Option Price Per Share, granted   8.40
Option Price Per Share, ending balance 104.00 $ 104.00
Option Price Per Share, exercisable $ 104.00