Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Oct. 01, 2018
Income Tax Disclosure [Line Items]
Deferred income taxes			$ 6,176,000	$ 6,304,000
Income tax receivable			$ 558,000	$ 1,152,000
U.S. federal statutory tax rate	21.00%	35.00%	21.00%	24.50%	35.00%
Discrete tax expense		$ 1,200,000		$ 1,600,000
Excess tax benefits (shortfalls) related to stock based compensation expense			$ 500,000	2,000,000	$ (200,000)
Deferred tax asset valuation allowance			$ 5,328,000	4,541,000
Net operating loss carryforwards, remaining period			9 years
Unrecognized tax benefits excluding interest and penalties that would impact effective tax rate			$ 2,100,000	1,400,000	1,200,000
Liability for unrecognized tax benefits to change significantly in the next 12 months			500,000	400,000	$ 500,000
Undistributed earnings in foreign subsidiaries			0	$ 0
Federal and State [Member] | 2034 [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards			$ 200,000
Net operating loss carryforwards, beginning of expiration year			2034
Federal and State [Member] | 2022 [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			$ 3,000,000
R&D Credit Carryforwards [Member] | Federal and State [Member] | 2029 [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforwards			$ 2,400,000
Tax credit carryforward, beginning of expiration year			2029
Adoption of ASC Topic 606 [Member]
Income Tax Disclosure [Line Items]
Deferred income taxes						$ 5,089,000
Income tax receivable						762,000
Impact of Adoption [Member] | Adoption of ASC Topic 606 [Member]
Income Tax Disclosure [Line Items]
Deferred income taxes			$ 1,200,000			(1,215,000)
Income tax receivable			$ 400,000			$ (390,000)