Stock-based compensation - Summary of Stock Option Activity Under Plan (Detail) - $ / shares shares in Thousands	6 Months Ended
	Jun. 30, 2022
Shares (in thousands)
Outstanding at beginning of period (in shares)	3,586
Granted (in shares)	967
Exercised (in shares)	(2)
Canceled or forfeited (in shares)	(1,482)
Outstanding at end of period (in shares)	3,069
Exercisable at end of period (in shares)	1,296
Vested and expected to vest at end of period (in shares)	3,069
Weighted- average exercise price per share
Outstanding at beginning of period (in dollars per share)	$ 39.23
Granted (in dollars per share)	7.48
Exercised (in dollars per share)	1.04
Canceled or forfeited (in dollars per share)	41.11
Outstanding at end of period (in dollars per share)	29.48
Exercisable at end of period (in dollars per share)	51.24
Vested and expected to vest at end of period (in dollars per share)	$ 29.48