Stock Based Compensation - Summary of Stock Option Activity (Detail)	3 Months Ended
	Mar. 31, 2020 $ / shares shares
Number of shares
Beginning balance (in shares) | shares	5,318,759
Options granted (in shares) | shares	571,316
Less:
Options exercised (in shares) | shares	504,127
Options canceled or expired (in shares) | shares	51,210
Ending balance (in shares) | shares	5,334,738
Exercisable at March 31, 2020 (in shares) | shares	2,535,621
Weighted Average Exercise Price
Weighted average exercise price, beginning balance (in dollars per share) | $ / shares	$ 9.97
Weighted average exercise price, granted (in dollars per share) | $ / shares	28.36
Less:
Weighted average exercise price, exercised (in dollars per share) | $ / shares	7.58
Weighted average exercise price, canceled or expired (in dollars per share) | $ / shares	14.61
Weighted average exercise price, ending balance (in dollars per share) | $ / shares	12.14
Weighted average exercise price, exercisable, ending balance (in dollars per share) | $ / shares	$ 8.35