Commitments and Contingencies - Additional Information (Detail)	1 Months Ended	3 Months Ended		6 Months Ended			12 Months Ended	48 Months Ended
	Nov. 30, 2017 USD ($) ft²	Mar. 31, 2019 USD ($) € / $	Mar. 31, 2018 USD ($)	Mar. 31, 2019 USD ($) € / $	Mar. 31, 2019 EUR (€)	Mar. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2023 USD ($)
Commitments And Contingencies [Line Items]
Settlement of claim		$ 400,000
License agreement commencement date				2006-03	2006-03
Annual minimum payments for licenses				$ 224,000	€ 200,000
Exchange rate relating to license payment | € / $		1.1217		1.1217
Future minimum payments associated with license		$ 2,000,000		$ 2,000,000
Rent expense related to operating leases		100,000	$ 100,000	200,000		$ 200,000
Other long-term liabilities		4,853,000		$ 4,853,000			$ 5,720,000
Eden Prairie Minnesota [Member]
Commitments And Contingencies [Line Items]
Square feet facility | ft²	36,000
Operating lease agreement term	10 years
Operating lease agreement commencement date	2018-05
Amount deposited into restricted cash account	$ 400,000
Patents [Member]
Commitments And Contingencies [Line Items]
Patent expiry date				2027-09	2027-09
Intellectual Property [Member] | Embolitech LLC [Member]
Commitments And Contingencies [Line Items]
Payments to acquire intellectual property assets				$ 5,000,000
Installment payment beginning period				2020-01	2020-01
Installment payment ending period				2023-12	2023-12
Contingent payments upon achievement of regulatory milestones				$ 2,000,000
Contingency period ending year				2033	2033
Other long-term liabilities		2,100,000		$ 2,100,000			2,900,000
Other current liabilities		1,000,000		1,000,000
Intellectual Property [Member] | Embolitech LLC [Member] | Scenario Forecast [Member]
Commitments And Contingencies [Line Items]
Estimated additional payment to acquire intellectual property assets								$ 3,500,000
Selling, general and administrative [Member]
Commitments And Contingencies [Line Items]
Claim accrual recorded in selling, general and other administrative expenses							1,000,000
Reduction in selling,general and administrative expenses		$ 600,000		$ 600,000
Other Accrued Liabilities [Member]
Commitments And Contingencies [Line Items]
Claim accrual recorded in other accrued liabilities							$ 1,000,000