Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-Average Shares Outstanding (Details)

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-Average Shares Outstanding (Details) - shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted-average shares outstanding	1,293,498	896,002
Options to Purchase Ordinary Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted-average shares outstanding	1,158,079	696,112
Unvested Restricted Ordinary Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted-average shares outstanding	34,162	143,076
Unvested Restricted Share Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted-average shares outstanding	31,367	36,924
Unvested Performance Restricted Share Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted-average shares outstanding	50,000
Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted-average shares outstanding	19,890	19,890

Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-Average Shares Outstanding (Details)