Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2017
Income Tax Disclosure [Line Items]
U.S. federal statutory tax rate	35.00%	21.00%	21.00%	24.50%	35.00%
Impact of CARES Act		$ 1,700,000
Discrete tax impact of enacted tax legislation				$ 1,600,000
Excess tax benefits related to stock based compensation expense		400,000	$ 500,000	2,000,000.0
Deferred tax asset valuation allowance		6,246,000	5,328,000
Unrecognized tax benefits that would impact effective tax rate		2,700,000	2,100,000	1,400,000
Accrued interest and penalties on unrecognized tax benefits		600,000	500,000	$ 400,000
Undistributed earnings in foreign subsidiaries		0	$ 0
Federal [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		$ 100,000
Net operating loss carryforwards, beginning of expiration year		2034
State [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		$ 200,000
Net operating loss carryforwards, beginning of expiration year		2022
Ireland and Luxembourg [Member] | Creagh Medical Ltd [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		$ 3,200,000
R&D Credit Carryforwards [Member] | Federal and State [Member] | 2029 [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforwards		$ 3,200,000
Tax credit carryforward, beginning of expiration year		2029