Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2015	Jan. 01, 2024	Dec. 31, 2023	Nov. 20, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value	$ 0.001		$ 0.001				$ 0.001
Common stock, shares outstanding	54,846,639		54,846,639				54,480,704
Common stock, shares issued	54,846,639		54,846,639				54,480,704
Number of options outstanding	4,259,562		4,259,562				7,897,647
Options granted			3,045,125
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 1,136	$ 2,834	$ 4,289	$ 8,436
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 353	$ 500	$ 2,285	$ 1,693
Employees And Non-Employee Members Of Board Of Directors [Member] | Share-based Payment Arrangement, Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of options granted		$ 2.24	$ 0.66	$ 5.86
Employees And Non-Employee Members Of Board Of Directors [Member] | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, grant date fair value			$ 0.66	$ 7.81
Non-employee Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	0	0	0	0
2014 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized						13,837,444	12,203,023
Number of stock options that may be granted after the tenth anniversary of the 2014 Plan			0
Annual increases in number of shares reserved for issuance as a percentage of shares of capital stock outstanding through January 1, 2024					3.00%
Options granted	0	155,747	3,045,125	1,954,668
2014 Equity Incentive Plan [Member] | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded	0	0	903,883	601,172
2014 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of awards granted			10 years
2014 Equity Incentive Plan [Member] | Maximum [Member] | Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized					30,000,000
2014 Equity Incentive Plan [Member] | Director [Member] | Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted			3 years
2014 Equity Incentive Plan [Member] | Employee And Nonemployee Consultants [Member] | Share-Based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vested shares on first anniversary of grant date			25.00%
2014 Equity Incentive Plan [Member] | Employee And Nonemployee Consultants [Member] | Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted			36 months
2014 Equity Incentive Plan [Member] | Employee And Nonemployee Consultants [Member] | Share Based Compensation Subsequent Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted			4 years
2014 Equity Incentive Plan [Member] | Employees And Non-Employee Members Of Board Of Directors [Member] | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded			903,883
Restricted stock units, grant date fair value			$ 0.66
2019 Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value								$ 0.001
Awarded	0	0	0	0
2019 Inducement Plan [Member] | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded	0	0	0	0
2019 Inducement Plan [Member] | Share-Based Compensation Award, Tranche One [Member] | Share-based Payment Arrangement, Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vested shares on first anniversary of grant date			25.00%
2019 Inducement Plan [Member] | Share-based Compensation Award, Tranche Two [Member] | Share-based Payment Arrangement, Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted			36 months
2019 Inducement Plan [Member] | Share Based Compensation Subsequent Awards [Member] | Share-based Payment Arrangement, Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted			4 years
2019 Inducement Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized								300,000