Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands													1 Months Ended													3 Months Ended						9 Months Ended		12 Months Ended
	Jun. 15, 2023 shares	Jun. 01, 2023 $ / shares shares	Mar. 01, 2023 $ / shares shares	Oct. 12, 2022 $ / shares shares	Jun. 15, 2022 $ / shares shares	Jun. 02, 2022 $ / shares shares	Mar. 31, 2022 shares	Feb. 25, 2022 installment $ / shares shares	Dec. 17, 2021 installment $ / shares shares	Oct. 29, 2021 tranche $ / shares shares	Jun. 03, 2021 $ / shares shares	Mar. 30, 2021 installment $ / shares shares	Aug. 31, 2023 shares	Jul. 31, 2023 shares	Jun. 30, 2023 shares	Apr. 30, 2023 shares	Mar. 31, 2023 shares	Feb. 28, 2023 shares	Jan. 31, 2023 shares	Dec. 31, 2022 $ / shares shares	Oct. 31, 2022 shares	Jun. 30, 2022 shares	Mar. 31, 2022 shares	Feb. 28, 2022 shares	Feb. 29, 2020 installment $ / shares shares	Sep. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2023 shares	Mar. 31, 2023 shares	Sep. 30, 2022 USD ($) $ / shares shares	Jun. 30, 2022 shares	Mar. 31, 2022 shares	Sep. 30, 2023 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2015 shares	Jan. 01, 2023 shares	Nov. 20, 2019 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value | $ / shares																				$ 0.001						$ 0.001						$ 0.001
Common stock, shares outstanding																				53,797,341						54,471,829						54,471,829
Common stock, shares issued																				53,797,341						54,471,829						54,471,829
Number of restricted stock units outstanding																										775,711			640,950			775,711	640,950
Number of options outstanding																				7,689,449						8,040,891			7,654,523			8,040,891	7,654,523
Options granted																																1,954,668
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued																										386,881
Restricted stock units vested shares																										16,142	94,454	83,793	7,500	89,075	109,943
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Forfeited																3,585
Board of Directors Chairman [Member] | Restricted Stock Units [Member] | June 2022 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units vested shares																						11,876
Employees [Member] | Restricted Stock Units [Member] | Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										$ 90			$ 200			$ 385	$ 565
Employees [Member] | Restricted Stock Units [Member] | General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										259			381			899	2,350
Director [Member] | Restricted Stock Units [Member] | General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										$ 151			$ 126			$ 409	$ 503
Director [Member] | Time-based Restricted Stock Units [Member] | June 2022 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted															1 year							1 year
Restricted stock units vested shares															59,380							43,200
Executive Officers [Member] | Time-based Restricted Stock Units [Member] | February 2022 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted																		3 years
Restricted stock units vested shares																		42,920
Executive Officers [Member] | Time-based Restricted Stock Units [Member] | December 2021 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units vested shares															26,199
Executive Officers [Member] | Time-based Restricted Stock Units [Member] | October 2022 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units vested shares													7,267
Executive Officers [Member] | Time-based Restricted Stock Units [Member] | March 2021 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted																												3 years
Restricted stock units vested shares																												15,999
Executive Officers [Member] | Time-based Restricted Stock Units [Member] | February 2020 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted																		3 years						3 years
Restricted stock units vested shares																		15,999						32,666
Non-employee Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted																										0			0			0	0
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 | $ / shares																										$ 2.24			$ 7.37			$ 5.86	$ 7.27
2019 Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value | $ / shares																																				$ 0.001
Awarded																										0			0			0	0
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
2019 Inducement Plan [Member] | Share-based Payment Arrangement, Employee [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%
2019 Inducement Plan [Member] | Share-based Payment Arrangement, Employee [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
2019 Inducement Plan [Member] | Share-based Payment Arrangement, Employee [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]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
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%
Share-based compensation arrangement by share-based payment award, number of shares authorized																				10,589,103															12,203,023
Options granted																										155,747			437,500			1,954,668	1,739,919
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] | Board of Directors Chairman [Member] | Restricted Stock Units [Member] | General and Administrative [Member] | June 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																																	$ 100
2014 Equity Incentive Plan [Member] | Employees [Member] | Performance Restricted Stock Units [Member] | February 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded								243,000
Restricted stock units, grant date fair value | $ / shares								$ 10.46
Compensation expense | $																										$ 0			$ 0			$ 0	0
Number of restricted stock units outstanding																										0						0
2014 Equity Incentive Plan [Member] | Employees [Member] | Performance Restricted Stock Units [Member] | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded												176,000
Restricted stock units, grant date fair value | $ / shares												$ 20.59
Compensation expense | $																										$ 0			0			$ 0
Restricted stock units, vested																								37,999
Restricted stock units, forfeited due to performance targets not getting met																							93,999
Number of restricted stock units outstanding																										0						0
2014 Equity Incentive Plan [Member] | Employees [Member] | Performance Restricted Stock Units [Member] | March 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded			407,000
Restricted stock units, grant date fair value | $ / shares			$ 10.06
Compensation expense | $																										$ 0						$ 0
Number of restricted stock units outstanding																										407,000						407,000
2014 Equity Incentive Plan [Member] | Employees [Member] | Performance Restricted Stock Units [Member] | General and Administrative [Member] | Modified November 2021 Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																																	303
2014 Equity Incentive Plan [Member] | Employees [Member] | Performance Restricted Stock Units [Member] | General and Administrative [Member] | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																																	729
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | February 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted								3 years
Awarded								145,170
Restricted stock units, grant date fair value | $ / shares								$ 10.46
Number of equal installment | installment								3
Compensation expense | $																										$ 103			116			$ 303	274
Restricted stock units, vested																		42,920
Number of restricted stock units outstanding																										78,665						78,665
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | December 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted									18 months
Awarded									63,573
Restricted stock units, grant date fair value | $ / shares									$ 12.45
Number of equal installment | installment									2
Compensation expense | $																										$ 0			110			$ 199	323
Restricted stock units, vested	26,199																															0
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted												3 years
Awarded												100,000
Restricted stock units, grant date fair value | $ / shares												$ 20.59
Number of equal installment | installment												3
Compensation expense | $																										83			83			$ 246	563
Restricted stock units, vested																						17,333	33,336									15,999
Restricted stock units, Forfeited																						17,333
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | February 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted																									3 years
Awarded																									98,000
Restricted stock units, grant date fair value | $ / shares																									$ 16.36
Number of equal installment | installment																									3
Compensation expense | $																										0			66			$ 39	460
Restricted stock units, vested																								32,666								0
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | Research and Development [Member] | February 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										35			48			$ 100	113
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | Research and Development [Member] | December 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																													53			96	157
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | Research and Development [Member] | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										55			55			164	164
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | Research and Development [Member] | February 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																													44			26	131
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | General and Administrative [Member] | Modified February 2020 Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																																	264
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | General and Administrative [Member] | Modified November 2021 Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																																	317
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | General and Administrative [Member] | February 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										68			68			203	161
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | General and Administrative [Member] | December 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																													57			103	166
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | General and Administrative [Member] | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										$ 28			28			82	399
2014 Equity Incentive Plan [Member] | Employees [Member] | Time-based Restricted Stock Units [Member] | General and Administrative [Member] | February 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																													22			$ 13	329
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] | Executive Officers [Member] | Time-based Restricted Stock Units [Member] | October 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded				7,267
Restricted stock units, grant date fair value | $ / shares				$ 9.42
Number of restricted stock units outstanding																										0						0
2014 Equity Incentive Plan [Member] | Executive Officers [Member] | Time-based Restricted Stock Units [Member] | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, vested																	15,999
2014 Equity Incentive Plan [Member] | Executive Officers [Member] | Time-based Restricted Stock Units [Member] | February 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, vested																		15,999
2014 Equity Incentive Plan [Member] | Executive Officers [Member] | Time-based Restricted Stock Units [Member] | General and Administrative [Member] | October 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										$ 13						$ 51
2014 Equity Incentive Plan [Member] | Former Chief Financial Officer [Member] | Performance Restricted Stock Units [Member] | February 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, Forfeited																						29,000
Restricted stock units, forfeited due to resignation of former CFO																						20,000
Restricted stock units, cancelled																				214,000
2014 Equity Incentive Plan [Member] | Former Chief Financial Officer [Member] | Time-based Restricted Stock Units [Member] | December 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, forfeited due to resignation of former CFO																						11,170
2014 Equity Incentive Plan [Member] | Interim Principal Financial and Accounting Officer [Member] | Time-based Restricted Stock Units [Member] | June 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded					7,500
Restricted stock units, grant date fair value | $ / shares					$ 7.94
Compensation expense | $																													55				60
Restricted stock units, vested																																0
2014 Equity Incentive Plan [Member] | Chief Executive Officer [Member] | Time-based Restricted Stock Units [Member] | October 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded										147,942
Restricted stock units, grant date fair value | $ / shares										$ 16.83
Number of restricted stock unit tranches | tranche										2
Restricted stock units, vested														8,875		8,875			8,875		35,500
Number of restricted stock units outstanding																										79,875						79,875
2014 Equity Incentive Plan [Member] | Chief Executive Officer [Member] | Time-based Restricted Stock Units [Member] | General and Administrative [Member] | October 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										$ 150			151			$ 446	506
2014 Equity Incentive Plan [Member] | Chief Executive Officer [Member] | Share-Based Compensation Award, Tranche One [Member] | Time-based Restricted Stock Units [Member] | October 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vested shares on first anniversary of grant date										25.00%
Awarded										142,000
2014 Equity Incentive Plan [Member] | Chief Executive Officer [Member] | Share-based Compensation Award, Tranche Two [Member] | Time-based Restricted Stock Units [Member] | October 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted										36 months
Restricted stock units, vested							5,942
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] | Non-employee Directors [Member] | Restricted Stock Units [Member] | June 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded						59,380
Restricted stock units, grant date fair value | $ / shares						$ 8.42
Compensation expense | $																										$ 0
Number of restricted stock units outstanding																										0						0
2014 Equity Incentive Plan [Member] | Non-employee Directors [Member] | Restricted Stock Units [Member] | June 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted											1 year
Awarded											43,200
Restricted stock units, grant date fair value | $ / shares											$ 13.06
Compensation expense | $																													0
Number of restricted stock units outstanding																										0						0
2014 Equity Incentive Plan [Member] | Non-employee Directors [Member] | Restricted Stock Units [Member] | June 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted		1 year
Awarded		194,172
Restricted stock units, grant date fair value | $ / shares		$ 3.09
Number of restricted stock units outstanding																										194,172						194,172
2014 Equity Incentive Plan [Member] | Non-employee Directors [Member] | Restricted Stock Units [Member] | General and Administrative [Member] | June 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																													$ 126			$ 209	164
2014 Equity Incentive Plan [Member] | Non-employee Directors [Member] | Restricted Stock Units [Member] | General and Administrative [Member] | June 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																																	$ 239
2014 Equity Incentive Plan [Member] | Non-employee Directors [Member] | Restricted Stock Units [Member] | General and Administrative [Member] | June 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $																										$ 151						$ 199
2014 Equity Incentive Plan [Member] | Employees And Non-Employee Members Of Board Of Directors [Member] | Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded																																601,172
Restricted stock units, grant date fair value | $ / shares																																$ 7.81
Restricted stock units, vested																																194,389
Restricted stock units, Forfeited																																3,585
Number of restricted stock units outstanding																				372,513						775,711						775,711