Net Loss Per Share - Summary of Number of Ordinary Shares Excluded from Computation of Earnings Per Share (Detail) - shares	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	2,817,343	4,052,500
Exercise Of Options To Purchase Ordinary Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	1,859,979	2,241,223
Restricted Share Units Awarded, Including Multi-Year Performance [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	781,839	1,085,752
Exercise Of Warrants At $16.14 Per Share [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	111,525	111,525
Exercise Of Warrants At $9.375 Per Share [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share	64,000	64,000
Exercise Of Warrants At $0.01 Per Share [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Ordinary shares issuable excluded from computation of earnings per share		550,000