Net Loss Per Share - Summary of Number of Ordinary Shares Excluded from Computation of Earnings Per Share (Detail) (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Exercise Of Warrants At $16.14 Per Share [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Exercise price of warrants per share	$ 16.14	$ 16.14
Exercise Of Warrants At $9.375 Per Share [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Exercise price of warrants per share	$ 9.375	9.375
Exercise Of Warrants At $0.01 Per Share [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Exercise price of warrants per share		$ 0.01