Organization - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Cash and cash equivalents	$ 76,054	$ 115,069
Accumulated deficit	$ (842,852)	$ (764,101)
Common stock, shares authorized	350,000,000	250,000,000
Common stock, shares outstanding	216,127,443	214,591,906
Common Stock
Common stock, shares authorized	350,000,000
Common stock, shares outstanding	216,127,443
Common stock reserved for future issuance	33,620,711