Net Income (Loss) Per Share Attributable to Common Shareholders - Schedule of Antidilutive Securities not Include in Computation of Net Income (Loss) per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities not include in computation of net income (loss) per share	3,897,754	7,016,653	6,419,854
Outstanding Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities not include in computation of net income (loss) per share	3,789,129	6,689,311	6,262,339
Unvested Restricted Common Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities not include in computation of net income (loss) per share	108,625	327,342	157,515