Quarterly report pursuant to Section 13 or 15(d)

Equity-Based Compensation - Additional Information (Detail)

v3.8.0.1
Equity-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 12 Months Ended
May 31, 2016
Aug. 31, 2015
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Nov. 02, 2012
Restricted Stock Units            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Compensation expense     $ 800 $ 810    
Unrecognized compensation expense related to unvested awards     $ 4,340   $ 5,140  
Recognition period of unrecognized compensation expense related to unvested awards     1 year 10 months 2 days   2 years 1 month 2 days  
2012 Equity Incentive Plan            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Shares reserved for issuance     690,077      
Shares reserved for issuance, authorized           1,687,500
Restricted stock units granted 3,791 966,510        
Fair Value per unit $ 13.19 $ 13.23        
Restricted stock units granted description     Twenty-five percent of the RSUs granted vest and settle on each of the first, second, third and fourth anniversaries of the grant date.      
2012 Equity Incentive Plan | Employee            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock units granted 7,582          
Fair Value per unit $ 13.19          
Restricted stock units granted description     Twenty-five percent of the RSUs granted vest and settle on each of the first, second, third and fourth anniversaries of the grant date.      
2012 Equity Incentive Plan | Board of Directors            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock units granted 3,000          
Fair Value per unit $ 13.19          
Restricted stock units granted description     One hundred percent of the RSUs granted vested and settled on the first anniversary of the grant date.      
2012 Equity Incentive Plan | First Anniversary            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 25.00% 25.00%        
2012 Equity Incentive Plan | First Anniversary | Employee            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 25.00%          
2012 Equity Incentive Plan | First Anniversary | Board of Directors            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 100.00%          
2012 Equity Incentive Plan | Second Anniversary            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 25.00% 25.00%        
2012 Equity Incentive Plan | Second Anniversary | Employee            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 25.00%          
2012 Equity Incentive Plan | Third Anniversary            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 25.00% 25.00%        
2012 Equity Incentive Plan | Third Anniversary | Employee            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 25.00%          
2012 Equity Incentive Plan | Fourth Anniversary            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 25.00% 25.00%        
2012 Equity Incentive Plan | Fourth Anniversary | Employee            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Restricted stock, vesting percentage 25.00%