Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Schedule of Weighted Average Price Per Unit (Detail)

v3.19.1
Stock-Based Compensation - Schedule of Weighted Average Price Per Unit (Detail) - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Weighted average price per unit $ 16.76 $ 8.00