Quarterly report pursuant to Section 13 or 15(d)

Equity-Based Compensation - Additional Information (Detail)

v3.21.2
Equity-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Aug. 31, 2021
May 31, 2021
Jan. 31, 2021
May 31, 2020
Mar. 31, 2020
May 31, 2019
Oct. 31, 2018
May 31, 2016
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Nov. 02, 2012
Class A Common Stock                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units granted                     13,462   8,242  
Class B Common Stock                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units granted                     170,854      
Non-Qualified Stock Options                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units granted       86,764   60,742 105,398              
Restricted stock units\non-qualified stock options, granted description             One third of the NQOs will vest and become exercisable on each of the first, second and third anniversaries of the grant date.       One third of the NQOs will vest and become exercisable on each of the first, second and third anniversaries of the grant date.      
Fair value assumptions, strike price       $ 10.18   $ 14.54 $ 13.97              
Fair value assumptions, risk free rate       0.64%   2.32% 2.94%              
Fair value assumptions, expiration       10 years   5 years 5 years              
Fair value assumptions, volatility       48.00%   34.20% 32.70%              
Compensation expense forfeiture rate       1.00%   1.00% 1.00%              
Compensation expense                 $ 1,107 $ 192 $ 1,107 $ 456    
Recognition period of unrecognized compensation expense related to unvested awards                 1 year 9 months 25 days       1 year 5 months 8 days  
Unrecognized compensation expense related to unvested awards                 $ 2,356   $ 2,356   $ 1,342  
Restricted Stock Units                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units granted                     152,739 57,358    
Compensation expense                 344 $ 192 $ 1,107 $ 456    
Unrecognized compensation expense related to unvested awards                 $ 2,356   $ 2,356   $ 1,342  
Recognition period of unrecognized compensation expense related to unvested awards                 1 year 9 months 25 days       1 year 5 months 8 days  
2012 Equity Incentive Plan                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Shares reserved for issuance                 192,689   192,689      
Shares reserved for issuance, authorized                           1,687,500
Restricted stock units granted               3,791            
Fair Value per unit               $ 13.19            
Restricted stock units\non-qualified stock options, granted description                     Twenty-five percent of the RSUs granted vested and settled 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   116,823 21,598 49,116   34,388   7,582            
Fair Value per unit   $ 13.91 $ 13.89 $ 10.11   $ 14.54   $ 13.19            
Restricted stock units\non-qualified stock options, granted description                     Twenty-five percent of the RSUs granted vested and settled on each of the first, second, third and fourth anniversaries of the grant date      
2012 Equity Incentive Plan | Employee | Class A Common Stock                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units granted   856                        
Fair Value per unit   $ 14.61                        
2012 Equity Incentive Plan | Employee | Class B Common Stock                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units granted 1,827 11,635                        
Fair Value per unit $ 15.96 $ 14.61                        
2012 Equity Incentive Plan | Employee | Restricted Stock Units                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units\non-qualified stock options, 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 | Restricted Stock Units | Class B Common Stock                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units\non-qualified stock options, granted description The RSUs vest and settle on the third anniversary of the grant date                   One third of the RSUs granted vest and settle on each of the first, second and third 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         8,242                  
Fair Value per unit         $ 11.83                  
2012 Equity Incentive Plan | Board of Directors | Restricted Stock Units                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock units\non-qualified stock options, granted description                     All of the RSUs granted vest on the third anniversary 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\non-qualified stock options, 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%            
2012 Equity Incentive Plan | First Anniversary | Employee                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock, vesting percentage   25.00%   25.00%   25.00%   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         0.33%                  
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%            
2012 Equity Incentive Plan | Second Anniversary | Employee                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock, vesting percentage   25.00%   25.00%   25.00%   25.00%            
2012 Equity Incentive Plan | Second Anniversary | Board of Directors                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock, vesting percentage         0.33%                  
2012 Equity Incentive Plan | Third Anniversary                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock, vesting percentage               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%   25.00%   25.00%   25.00%            
2012 Equity Incentive Plan | Third Anniversary | Board of Directors                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock, vesting percentage         0.33%                  
2012 Equity Incentive Plan | Fourth Anniversary                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock, vesting percentage               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%   25.00%   25.00%   25.00%            
2012 Equity Incentive Plan | Fourth Anniversary | Board of Directors                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Restricted stock, vesting percentage         0.33%