Equity Incentive Awards - Summary of Stock Options Activity (Detail) shares in Thousands	6 Months Ended
	Jun. 30, 2021 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Options Outstanding [Roll Forward]
Beginning balance (in shares) | shares	10,432
Options granted (in shares) | shares	5,253
Options exercised (in shares) | shares	(9)
Options forfeited (in shares) | shares	(1,241)
Ending balance (in shares) | shares	14,435
Exercisable (in shares) | shares	5,654
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning balance (in USD per share) | $ / shares	$ 11.65
Options granted (in USD per share) | $ / shares	9.70
Options exercised (in USD per share) | $ / shares	5.86
Options forfeited (in USD per share) | $ / shares	10.87
Ending balance (in USD per share) | $ / shares	11.01
Exercisable (in USD per share) | $ / shares	$ 10.16