Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.19.1
Subsequent Events - Additional Information (Detail) - Employee Stock Option [Member] - shares
May 08, 2019
Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by share-based payment award, number of shares authorized   5,000,000
Subsequent Event [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of additional shares authorized 3,000,000  
Share-based compensation arrangement by share-based payment award, number of shares authorized 8,000,000