v3.20.2
Debt - Summary of outstanding debt (Detail) - USD ($)
$ in Thousands
Sep. 30, 2020
Dec. 31, 2019
Debt Disclosure [Abstract]    
Principal amount $ 200,000 $ 400,000
Unamortized discount (2,247) (3,935)
Carrying value of debt $ 197,753 $ 396,065