Stock-Based and Incentive Compensation - Narrative (Detail)								3 Months Ended		12 Months Ended
	Feb. 16, 2025	Dec. 10, 2024	Feb. 16, 2024	Dec. 10, 2023	Feb. 16, 2023	Dec. 10, 2022	Mar. 31, 2018	Mar. 31, 2022 USD ($) d Installment Tranche shares	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Oct. 31, 2018 shares	Oct. 04, 2018 USD ($)	Jun. 30, 2018 shares	Jun. 30, 2017 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted under plan (in options)								147,660
Share-based compensation arrangement by share-based payment award, purchase period							6 months
Total stock-based compensation expense | $								$ 2,469,000	$ 1,599,000
2009 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant								36,539
2018 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares, authorized													943,294
Number of shares available for grant								423,331
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum							3.00%
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested share-based arrangements | $								$ 22,800,000
Weighted average compensation cost recognition period (in years)								1 year 9 months 18 days
2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance								274,050
2015 Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted under plan (in options)								103,860
2015 Plan | RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted under plan (in RSUs)								2,730,940
2015 Plan | RSU | Tranche One | Forecast
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting ratio						0.333
2015 Plan | RSU | Tranche One | Forecast | Non-Executive Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional Vesting ratio					0.333
2015 Plan | RSU | Tranche Two | Forecast
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting ratio				0.333
2015 Plan | RSU | Tranche Two | Forecast | Non-Executive Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional Vesting ratio			0.333
2015 Plan | RSU | Tranche Three | Forecast
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting ratio		0.333
2015 Plan | RSU | Tranche Three | Forecast | Non-Executive Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting ratio	0.333
2015 Plan | PRSUs | Tranche One | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting ratio								0.6
2015 Plan | PRSUs | Tranche Two | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting ratio								0.182
2015 Plan | PRSUs | Tranche Three | March 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting ratio								0.182
2015 Plan | Minimum | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based vesting period (in years)								1 year
2015 Plan | Maximum | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based vesting period (in years)								4 years
2015 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares, authorized								341,500
2015 Inducement Plan | New Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options reserved for future issuance (in options)								360,000
2015 Inducement Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based vesting period (in years)								1 year
2017 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares, authorized								970,277
2017 Inducement Plan | Employees Entering into Employment Or Returning to Employment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options reserved for future issuance (in options)								1,800,000
2017 Inducement Plan | Tranche One | Employees Entering into Employment Or Returning to Employment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options reserved for future issuance (in options)														550,000
2017 Inducement Plan | Tranche Two | Employees Entering into Employment Or Returning to Employment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options reserved for future issuance (in options)											500,000
2017 Inducement Plan | Tranche Three | Employees Entering into Employment Or Returning to Employment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options reserved for future issuance (in options)								750,000
2017 Inducement Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted under plan (in options)								43,800
2017 Inducement Plan | RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted under plan (in RSUs)								48,900
Time-based vesting period (in years)								3 years
Vesting percentage								100.00%
2017 Inducement Plan | Minimum | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based vesting period (in years)								1 year
2017 Inducement Plan | Maximum | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based vesting period (in years)								4 years
Revenue Performance Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage								100.00%
Number of tranches | Tranche								2
Employment termination description								If a participant’s employment terminates prior to December 31, 2022 due to death or disability, the participant will automatically vest in an additional 25% of each tranche of his or her award.
Percentage of additional performance-based cash incentive awards								25.00%
Revenue incentive plan upon achievement of milestone description								Upon the achievement of a Tranche 1 or Tranche 2 milestone (but not a deemed achievement in connection with a change of control), each participant’s payout in respect of the applicable tranche of his or her award will equal (a) the participant’s then-vested percentage, multiplied by (b) $25 million, multiplied by (c) the participant’s individual percentage allocation of the incentive pool
Payout of revenues to participants | $								$ 25,000,000
Number of trailing days | d								20
Percentage of cash and registered securities of aggregate payment								50.00%
Total stock-based compensation expense | $								$ 21,900,000	$ 0	$ 21,800,000
Revenue Performance Incentive Plan | Tranche 1 Milestone
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equal installments | Installment								4
Percentage of milestone deemed to be achieved if milestone not achieved prior to change of control								50.00%
Base amount for dividing cumulative product revenue if milestone not achieved prior to change of control | $								$ 300,000,000
Payout of revenues to participants | $								$ 25,000,000
Revenue Performance Incentive Plan | Tranche 2 Milestone
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equal installments | Installment								4
Percentage of milestone deemed to be achieved if milestone not achieved prior to change of control								30.00%
Base amount for dividing cumulative product revenue if milestone not achieved prior to change of control | $								$ 600,000,000
Payout of revenues to participants | $								25,000,000
Revenue Performance Incentive Plan | Minimum | Tranche 1 Milestone
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative net product revenues | $								300,000,000
Revenue Performance Incentive Plan | Minimum | Tranche 2 Milestone
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative net product revenues | $								$ 600,000,000
Revenue Performance Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive pool amount plus accrued interest | $												$ 50,000,000