Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Additional Information (Detail)

v3.8.0.1
Stock-based Compensation - Additional Information (Detail) - USD ($)
 3 Months Ended
Feb. 09, 2017
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]            
Stock option awards   0       0
Stock options vested   33,330        
Stock options forfeited   0        
Number of stock options, exercised   0        
2012 Equity Incentive Plan [Member] | Non-employee Directors [Member]            
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]            
Annual retainer amount for the threshold of stock precluded from selling   $ 270,000        
2012 Equity Incentive Plan [Member] | Non-employee Directors [Member] | Restricted Stock [Member]            
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]            
Restricted shares awarded to each non-employee director 40,000          
Restricted shares vest in each quarter end     10,000 10,000 10,000 10,000
Restricted shares vesting rights   Under the Company's 2012 Equity Incentive Plan (the "2012 Plan"), of which, 10,000 restricted shares vested at the end of each calendar quarter in 2017, as each recipient remained a director through the vesting date.