Commitments and Contingencies - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended			48 Months Ended
	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2024
Commitments And Contingencies [Line Items]
Payments to acquire in-process research and development			$ 750,000	$ 5,000,000
Acquisition charge for in-process of research and development			890,000	7,888,000
Other accrued liabilities current	$ 4,790,000	$ 5,547,000	4,790,000
Other long-term liabilities	5,512,000	8,020,000	5,512,000
Litigation [Member]
Commitments And Contingencies [Line Items]
Settlement of claim			400,000
Selling, general and administrative [Member]
Commitments And Contingencies [Line Items]
Claim accrual recorded in selling, general and other administrative expenses				1,000,000.0
Reduction in selling, general and administrative expenses			600,000
Embolitech LLC [Member]
Commitments And Contingencies [Line Items]
Contingent payments upon achievement of regulatory milestones		$ 1,000,000.0
Installment payment beginning period		2021
Installment payment ending period		2024
CRO [Member]
Commitments And Contingencies [Line Items]
Contractual obligation remaining to be paid		$ 10,000,000
CRO [Member] | Minimum [Member]
Commitments And Contingencies [Line Items]
Gross contractual obligation		35,000,000
CRO [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Gross contractual obligation		40,000,000
CRO [Member] | Maximum [Member] | CRO Pass-through Expenses [Member]
Commitments And Contingencies [Line Items]
Gross contractual obligation		$ 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				5,000,000.0
Contingency period ending year		2033
Acquisition charge for in-process of research and development				$ 7,900,000
Contingent obligation due and payable as a result of achievement of regulatory milestone(s)		$ 1,000,000.0
Other accrued liabilities current	1,000,000.0	1,100,000	1,000,000.0
Other long-term liabilities	2,100,000	$ 2,200,000	2,100,000
In-Process Research and Development [Member] | Embolitech LLC [Member] | Forecast [Member]
Commitments And Contingencies [Line Items]
Contractual obligation payable in fiscal 2021 through fiscal 2024					$ 3,500,000
In-Process Research and Development [Member] | InnoCore Technologies BV [Member]
Commitments And Contingencies [Line Items]
License agreement commencement year		2006
Annual minimum payments for licenses		$ 200,000
Patent expiry date		2027-05
Future minimum payments associated with license		$ 1,700,000
In-Process Research and Development [Member] | Medical Device [Member]
Commitments And Contingencies [Line Items]
Payments to acquire in-process research and development			800,000
Contingent payments upon achievement of regulatory milestones			1,300,000
Contingency period ending year		2022
Estimated additional payment to acquire intellectual property assets			200,000
Acquisition charge for in-process of research and development	$ 900,000		$ 900,000