Commitments and Contingencies - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended	12 Months Ended			36 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Dec. 31, 2020	Mar. 31, 2022	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2024
Embolitech LLC [Member]
Commitments And Contingencies [Line Items]
Contingent payments upon achievement of regulatory milestones				$ 1,000,000.0
Installment payment beginning period				2023
Installment payment ending period				2024
CRO [Member]
Commitments And Contingencies [Line Items]
Contractual obligation remaining to be paid		$ 9,000,000		$ 9,000,000
CRO [Member] | Minimum [Member]
Commitments And Contingencies [Line Items]
Gross contractual obligation		37,000,000		37,000,000
CRO [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Gross contractual obligation		40,000,000		40,000,000
CRO [Member] | Maximum [Member] | CRO Pass-through Expenses [Member]
Commitments And Contingencies [Line Items]
Gross contractual obligation		30,000,000		$ 30,000,000
In-Process Research and Development [Member] | Embolitech LLC [Member]
Commitments And Contingencies [Line Items]
Payments to acquire in-process research and development		$ 500,000	$ 1,000,000.0		$ 1,000,000.0		$ 5,000,000.0
Contingency period ending year				2033
In-Process Research and Development [Member] | Embolitech LLC [Member] | Forecast [Member]
Commitments And Contingencies [Line Items]
Contractual obligation payable in fiscal 2022 through fiscal 2024								$ 2,000,000.0
In-Process Research and Development [Member] | Medical Device [Member]
Commitments And Contingencies [Line Items]
Payments to acquire in-process research and development			$ 200,000			$ 800,000
Contingency period ending year				2022
In-Process Research and Development [Member] | Medical Device [Member] | Forecast [Member]
Commitments And Contingencies [Line Items]
Contingent payments upon achievement of regulatory milestones	$ 1,100,000