Stock-Based Compensation - Summary of Weighted Average Assumptions Used to Compute Fair Value of Option Granted (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Risk-free interest rate	4.00%		4.20%	4.40%
Expected term	6 years		6 years	6 years
Expected volatility of underlying stock	75.80%		76.30%	78.70%
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	5.37%	5.53%
Risk-free interest rate, Minimum			5.24%	4.70%
Risk-free interest rate , Maximum			5.37%	5.53%
Expected term	6 months	6 months	6 months	6 months
Expected volatility of underlying stock	59.00%	60.40%
Expected volatility of underlying stock, Minimum			56.70%	60.40%
Expected volatility of underlying stock, Maximum			59.00%	69.20%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%