Summary of Significant Accounting Policies - Impact of Topic 606 Adoption on Financial Statements (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accumulated deficit	$ (842,852)	$ (764,101)
Collaboration revenue	398	0
Net loss	(78,751)	(79,976)
Net income (loss) applicable to common shareholders	(78,751)	(79,976)
Net Income (Loss) Attributable to Parent	$ (78,751)	$ (79,976)