Stock-Based Compensation - Summary of Weighted Average Assumptions Used to Compute Fair Value of Option Granted (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Risk-free interest rate	4.40%	1.90%	1.00%
Expected term	6 years	5 years 10 months 24 days	6 years
Expected volatility of underlying stock	78.70%	76.20%	72.90%
Expected dividend yield	0.00%	0.00%	0.00%
2016 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Risk-free interest rate, Minimum	4.70%	0.22%	0.05%
Risk-free interest rate , Maximum	5.53%	2.52%	0.09%
Expected term	6 months	6 months	6 months
Expected volatility of underlying stock, Minimum	60.40%	63.60%	77.50%
Expected volatility of underlying stock, Maximum	69.20%	95.30%	109.20%
Expected dividend yield	0.00%	0.00%	0.00%