Annual report pursuant to Section 13 and 15(d)

Stock Based Compensation -Summary of Stock-based Compensation Costs Recognized (Detail)

v3.10.0.1
Stock Based Compensation -Summary of Stock-based Compensation Costs Recognized (Detail) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Total $ 16,753,754 $ 15,802,819
Employee Stock Option [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Allocated share-based compensation expense 0 764,723
Restricted Stock Units (RSUs) [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Allocated share-based compensation expense 15,359,011 13,043,171
Performance Share Units [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Allocated share-based compensation expense 819,816 1,661,650
Deferred Stock Units [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Allocated share-based compensation expense 0 1,362
Employee Stock Purchase Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Allocated share-based compensation expense $ 574,927 $ 331,913