Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation - Performance Share Units - Additional Information (Detail)

v3.19.2
Stock Based Compensation - Performance Share Units - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Performance Share Units [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated share-based compensation expense $ 0 $ 204,954 $ 0 $ 407,656